Solo Artificer
I really have no idea what all of you are talking about, my doppelganger artificer (forget you all, it's a doppelganger not a changeling, that's something different -.-) is actually quite capable of surviving on her own fairly well at level 12. And that's with the Chameleon paragon, basically meaning my path powers are useless without team mates.
I personally don't have a ranged weapon, but rather pack a scythe (house ruled to count as a staff for magic properities. I mean, a staff is a stick. A scythe is a stick with a blade on it..). Wickedly high Int mod and enchanted leather armor gave me a fairly decent AC. As for the whole not so useful Resistive Formula.. +1 AC in addition to that from Thundering Armor (most artificer powers CAN target you as well, "You or an Ally..") means I generally shrugged off quite a few attacks. A few summons, a sigil on my weapon and I was quite fine with all my comrades down.
Though should I ever get into a sticky situation, I always was quite glad to be facing humanoids.. Shapeshift with a massively high Bluff bonus. Which, even with a forced penalty from being SEEN shapeshifting (sometimes I used smoke bombs. Alchemist, mwahaha) I was still able to outroll, easily, any enemy that tried to insight me. Basically... "He's the impostor. I'm totally serious.." I think it failed maybe.. Only a handful of times on me.
The artificer is a little more limited in healing compared to a cleric, what with having to spend his/her healing surges or have an ally spend theirs to regain their healing ability back.
But for all you doubters.. Behold the scary.
Artificer attack 29, Simulacrum.
You create a Medium simulacrum in an unoccupied square within range. The simulacrum has whatever speed and modes of movement you have have without bonuses or penalties. The simulacrum has nonmagical copies of any implements or weapons you possessed at the time of its creation. These disappear when this power ends or when they are removed from the simulacrum.
A simulacrum uses a Standard action for special commands, able to use an at-will or encounter artificer power that you know, regardless of whether you used it (able to use encounter powers only once each). The simulacrum's use of an encounter attack power does not count towards your use of that power. It uses your attack bonus with the power.
It can also use Daily powers (except Simulacrum), but once it does the Simulacrum power ends. It also is capable of Opportunity Attacks.
Now.. An artificer is an arcane based class, meaning they can take the epic path of Archspell. The focus spell of the path can be retuned to any power at a level up. The specialization spell of an Archspell can be used twice per day. And if you die.. You return with the spell available, as well, with half health. A minimum of two Simulacrum spells per day. That gives an artificer a lot of weight in those extremely difficult battles, especially since a Simulacrum can use healing powers, too.. Picture it. The artificer themself, and two Simulacrums in a single battle, slinging a heavy array of powers, the same encounter spell, even, three times in three turns (twice if one has Action point). And before a simulacrum is killed.. They each can use a daily to vanish without the artificer suffering a healing surge loss.
I've never reached that level, but I have witnessed it in a battle against Orcus. It's pretty handy having two copies of yourself, each capable of the Daily healing utility Hero's Elixir (spend a healing surge, regain FULL health. Half if no surges). It was pretty amusing, really. Especially with the warlord using the simulacrum's as extras for those "ally takes an opportunity attack" powers they have.
He had a lot of summons out...
Artificers are fun to flavor.