Sorry for the slight threadjack.
wildstarsreach: Obviously your shaper isn't really maximized to make use of Astral Construct, so it's a fairly average example. Not really a good indication of broken-ness or lack thereof.
The wizard's or druid's summons will of course be capable of some more utility, but I'm not sure the 6th-level summons will be able to come very close to one or more 7th or 8th level Astral Constructs' combat power and durability. See below.
[sblock]What a different 11th-level character can do with the power: First, a Shaper 11, then a Wilder 11.
Human Shaper 11
Feats: Boost Construct (bonus, human), Overchannel (bonus, 1st), Talented (1st), Psicrystal Affinity (3rd), Psicrystal Containment (bonus, 5th), Improved Initiative (6th), Psionic Meditation (9th), and Quicken Power (bonus, 10th).
Relevant Powers: Astral Construct, Psionic Repair Damage, Ecto Protection, and Share Pain (so your astral constructs can take half of the damage dealt to you, in your stead).
Manifest a 7th-level Astral Construct using the Astral Construct power, fully augmented, with Overchannel and expending psionic focus for the Talented feat, to negate the backlash damage you'd otherwise take from overchanneling. However, expend your psicrystal's psionic focus instead of your own, via the Psicrystal Containment feat.
At the same time, roughly, manifest Ecto Protection (it specifically has the capacity to be manifested as a swift action when manifesting Astral Construct), augmented as much as you see fit, to ensure any opposing psions have a really tough time with any attempt to use Dismiss Ectoplasm against it.
Next round, manifest Share Pain as a swift action, using Quicken Power, which expends your psionic focus. Now your Astral Construct is an even better damage-soaker for you. Follow through by manifesting whatever you please, such as Psionic Repair Damage if your Astral Construct is sufficiently damaged already to warrant it. Regain your psionic focus first with a move-equivalent action. If you end up manifesting Psionic Repair Damage this round, you'll be able to expend your psionic focus again for the Talented feat in order to augment your PRD power to the max with Overchannel. But of course you'll have to do the refocusing before the PRD manifesting in that case.
Following that round, you can just remanifest Psionic Repair Damage with Talented/Overchannel when needed, even manifest a Quickened Psionic Repair Damage in the same round (though it'll be less fully augmented, since 6 points will go towards Quicken Power, so you can only augment the Quickened copy up to 5d8+13 hp repaired). Congratulations, your Astral Construct is pretty significantly durable and is not likely to be destroyed any time before its normal duration expires.
Now, if you don't use the Complete Psionic restriction (IIRC) that limits you to having only 1 Astral Construct active at any given time, you can just go ahead and manifest a Quickened 3rd-level Astral Construct each round after the first or second, alongside another 7th-level Astral Construct in one of those rounds (which will require expending your psicrystal's psionic focus, from Psicrystal Containment, for the Talented feat in that round, after you already use your own focus earlier in the round for the Quickened Astral Construct). Or just manifest another 7th-level Astral Construct every other round (since you'll need to regain psionic focus on every other round, given the manifestation time of non-Quickened Astral Constructs).
If you use an 11th-level Wilder as the example, it's just a bit different in effect. No Overchannel, Talented, Psicrystal Affinity, Psicrystal Containment, or Psionic Meditation feats, as they'll lack 3 bonus feats from the Psion class, and will need to replace 2 of their feats with Expanded Knowledge to learn Astral Construct and Psionic Repair Damage. Improved Initiative would be their 1st-level feat in that case, Quickened Power their 3rd-level feat, and Expanded Knowledge as their 6th and 9th level feats. Boost Construct would still be their human bonus feat.
However, the Wilder will be able to Wild Surge for +4 manifester levels, as opposed to the +2 the Shaper Psion would get from Overchannel. This means an 8th-level Astral Construct each round instead of a 7th-level one. The Wilder won't be able to manifest powers quite as rapidly as the Shaper Psion, for lack of the latter's boosts to psionic focus (through the bonus feats), but he or she can still keep their Astral Construct pretty well healed, and of course they'll be beefier, 8th-level Astral Constructs to begin with.
Here are likely 7th and 8th level Astral Constructs that these guys could manifest.
7th-level AS: Large Construct, 13d10+30 HD (101 HP), +1 Initiative, 40 ft. speed, AC 27, BAB/Grapple of +9 and +25, 2 slams +20 melee (1d8+12 damage each), DR 10/magic, darkvision 60 ft., low-light vision, construct immunities, one special ability from Menu C, bonus special ability from Boost Construct, saves F/R/W +4/+5/+4, Str 35/Dex 13/Wis 11/Cha 10, CR 8.
Likely abilities from Menu C: Either Power Resistance (PR 23, pretty good for a normally-11th-level manifester to grant, but only situationally effective), or Extreme Deflection (+8 AC, making for 35 total AC, may be tough for 11th-level foes to hit), or Constrict (going to be tough for 11th-level foes to oppose its +25 grapple bonus, unless they're giants/dragons/similarly-massive-guys themselves, so they're going to be a-hurtin', and rather less effective in combat than if the Astral Construct hadn'a grabbed 'em and started givin' the ole' spine-crushing bear hug), OR, most likely, 2 choices from Menu B.
Likely abilities from Menu B instead: Extra Attack, and 2 choices from Menu A.
Likely abilities from Menu A: Power Attack, and either Trip (most likely) or Improved Slam Attack. This is going to significantly boost the damage output, when combined with Extra Attack.
The bonus ability from Boost Construct, due to its wording, would likely be Muscle (+4 Str), Heavy Deflection (+4 AC), or Improved Slam Attack (assuming Trip was the second A-menu ability chosen). I would figure Improved Slam Attack to be most effective (1d8 base damage with slams goes up to 2d6), though Muscle has its merits too (a bit less damage, but +2 on the melee attack rolls and on grapple checks). If the manifester actually chooses a Menu C ability instead of going for several lower-menu-but-superior powers, then the bonus ability would probably be Rend.
I'll assume that Extra Attack, Power Attack, Trip, and Improved Slam Attack were chosen.
So most likely, the Astral Construct will be attacking 3 times per round at +15 for 2d6+17 damage, or +11 for 2d6+21 damage. The former two assume Power Attack + Trip (to where they knock down the opponent most likely with their first Slam, then hit them even more easily and just as hard with the next 2 Slams that round), while the latter two assume Power Attack + Improved Slam Attack. So overall, putting out roughly 6d6+48, or 6d6+62 damage each round with full attacks.
Also, note that with 3 attacks per round, the chances of a critical hit at some point in the battle are decent (though not great, given their threat range; Improved Critical won't boost that chance enough to be worthwhile, thus why I ignore it as an Astral Construct option).
The 8th-level Astral Constructs will have the same special abilities, but slightly better base stats... 16 HD, 118 HP, 29 AC (37 if Extreme Deflection is their special ability, or 33 if Heavy Deflection is taken instead), BAB/Grapple of +12/+30, an extra +5 on their Slam attack bonus, an extra +2 damage per Slam attack, DR improved to 15/magic, saves increased by +1 each, Str 39 instead of 35, and CR of 9 instead of 8.
As such, they could afford to Power Attack for 3 additional points, dealing out a total of 15 more damage per round than the 7th-level Astral Construct I described above. Not much more effective, but still a bit tougher, a bit more damaging, and a bit more accurate in their attacks (though only +2 more on attack rolls after considering a full Power Attack). Definitely better at grappling though, if they go with Constrict as their special ability.
An 11th-level wizard's Celestial Polar Bear, or other such summon, seems kinda weak by comparison. 2 Hound Archons would do slightly less damage it seems, and have much lower average damage, as well as simply not hitting nearly as often. 3 Celestial Lions seem to have similar problems, only worse. As well as all of those having pathetic ACs and total combined HP, compared to the Astral Constructs above. Sure, the manifester will use up their power points more quickly, but they can still out-fight the summoner most likely.
Of course, all these summons lack a Construct's numerous immunities to special attacks and whatnot, as well. And it's tougher for a party's cleric to heal multiple summoned monsters than for a psionic manifester to greatly repair a single Astral Construct at a time (or 2, which they could do; one Psionic Repair Damage normally, and one Quickened Psionic Repair Damage; if they position themselves decently, they can be within melee reach of 2 of their Astral Constructs).
Druids have similar problems. A huge earth elemental is less effective than a 7th or 8th level Astral Construct, though it does have around 40-50% more HP (with a reduction in its AC of 9 or 11 points, however, so it's comparatively much easier to hit). Dire bears are somewhat better than earth elementals for offense, but on par with Astral Constructs in HP, and still have lower ACs and somewhat lower damage than an Astral Construct. Two polar bears are similar to an Astral Construct in damage output (slightly better than one that doesn't power attack for much, slightly worse otherwise), have slightly lower attack bonuses (moreso with the bite attacks), and have terrible AC by comparison. Summoning 3 dire apes or whatnot is similar to the wizard summoning 3 celestial lions, though slightly better, just not as good as a 7th or 8th level Astral Construct.[/sblock]
My basic point is, you kinda need to weaken or limit Astral Constructs somehow. 1st-level Astral Constructs you create early on will not likely stick around long enough for their good HP to matter much, anyway, and shouldn't be dishing out too much damage for their comparative cost (1 power point out of your small handful of them, and 1 full round per manifestation; only lasting 1 or 2 rounds early on). So I'm less concerned about them.
If you don't focus much on your Astral Constructs, they won't be a problem, but otherwise the DM has the responsibility to handle any problems with powergaming (in that it can frustrate his efforts to provide challenges for the whole party, and make other players upset that their characters are being outshone all the time; a fighter doesn't like to be outdone in melee by a spellcaster's or manifester's conjured/created minion, and a wizard doesn't like being out-nuked by a psion or wilder, etc.).
This, er, concludes the lesson for today.
People that love psionics just *love* psionics, so..... 
