A full spellcaster with access to things as powerful as Hexes at 18 out of 21? Absolutely, positively not. I also disagree vehemently with Summoner at 20.
But just the fact that this conversation even exists in Pathfinder shows how much of a step up it is from 3.0, and even 3.5 in my opinion.
...Aaaaaaaaaaaaaaaand that's about my limit for posts I can read extolling Pathfinder's superior balance and design qualities.
Pathfinder has neither going for it, and is horribly unbalanced. Yeah, you got some new faces at the top like the summoner, but in the end, it's still the full spellcasters at the top.
In 3E, it took a lot of obscure splat books to find a race that raised a mental stat without costing LA or racial HD. Grey Elf and Fire Elf for Int were the easiest to find, but at least were balanced with a painful con loss and the general suckiness that is the elven racial features. Charisma you had like...Spellscales? Some things out there, but not common. Wisdom? I think you actually had to go back to 3.0 and the horrifically unbalanced Savage Species to find something for that, the anthro animals. I don't know Tortles and Buomann I think had wisdom bonus... In Pathfinder, ANY caster can have a 20 in their casting stat, very easily!
Pathfinder also nerfed the combat maneuver feats by breaking them up into 2. You need THREE freaking feats just to push someone so your allies can AoO him now, something you could do with NO feats in 3E! The CMB system itself is borked, so many things add to CMD that in my experience, actually succeeding at combat maneuvers requires extremely high specialization just to get like a 60% success rate. Grapple was horrifically nerfed, it's a standard now, not an attack replacement, you need to waste an action and risk a failed roll each round to "maintain," and being grappled isn't nearly as much of a hindrance as it used to be. These are all very major areas of martial combat that PF outright nerfed the hell out of, to the detriment of noncasters. Caster feats weren't really hurt at all. Heck, they added some sweet new ones. Like that one I mentioned to speak in wildshape. Or a +1 level metamagic to bounce a failed targeted spell to a new target. Or the +2 level metamagic to just plain require 2 successful rolls instead of one.
PF did give more stuff to pad out the mid and higher levels for martial classes, yes. But they also completely demolished most of the benefit of multiclassing, and made prestige classes pretty clearly inferior to just sticking in the same class instead. Maybe those are good things, but my point is... noncasters were the ones who multiclassed like crazy in 3E, they were the ones who could afford to do so and got great benefits from doing so. Any gains the martial classes got in PF came at the expense of multiclassing be much less viable, so in the end, the power level hasn't really changed. It's just more newbie friendly and easy to obtain. Again, that's fine and all, but stop saying melee got buffed in PF. It did not.
Finally, everyone always complains about the system mastery and "trap" options of 3E. Would you believe that PF is actually worse in this regard? Because it is. 3E at least tried to make options that were balanced (but turned out to not be because the designer just wasn't very good at measuring balance) or at least useful to someone, somewhere. The much maligned Toughness feat was great for wizards in 1st level one shot games, which IME are not THAT uncommon. Pathfinder is not like that, though. They care more about "flavor" and "roleplaying" than how powerful or worthless some mechanic is. Let's start with the worst example in possibly all of tabletop gaming history -- the monk Vow of Poverty. The designers explicitly knew the rule they were writing sucked and that it was a ridiculous power down for anyone that took it. But wrote it the way they did anyway, because they were balancing it on "roleplaying" terms -- if you want to RP someone that gives up most material possessions, you SHOULD suffer...just close your eyes and ignore the cleric, druid, paladin, and other myriad examples we printed that make seemingly arbitrary self-restrictions and are repaid handsomely for them -- rather than being mechanically balanced. At least the 3E designers of VoP TRIED to make its benefits commensurate with what you were losing and simply failed to understand how great a loss magic items were. PF just didn't even care about thinking about that.
Look at all the archetypes that are just pathetic. The archetypes that make you give something up at one level, but not get the replacement benefit until several later -- or in some cases, vice versa. Look at the embarassing number of corrections they need to make with each released book, despite pending more time on development of said books than WotC and putting out much fewer of them. How can you honestly say PF is a better designed game?