Power creep is irrelevant in Diablo/WoW games. What the 2.2 patch does is correct the woeful imbalance of the sets for each class. Rather than just having a single set that is actually useful at the high end, you can now choose a multitude of sets to play with depending on your playstyle. This is a great thing, and has been long needed.
Yes, it'll come at the cost of more players having access to GR40+ level ranges, but who cares? All Blizzard has to do is increase the cap to GR60. Besides, they always do large power boosts right before they announce/release expansions.
Power creep is relevant, on my view, because what people tend to see in isolation is something like:
Wizard before - firebird for grift; now, tal rasha. So more boom less dot.
DH before - huge dps, in season 3 it's actually buffed higher with Nats and increased survivability.
But firebird and dh dps were incomparable before. And the dancing needed with Tal Rasha compared to other sets is still a joke. A well geared Raekor barb (so imagine last 'era' already) will still be able to clear faster than Tal Rasha, because the nature of a Tal Rasha wizard is to generate the falling meteors. Look at even someone like Reiko Zockt, his Tal Rasha 2.2 (from PTR). Compare that then to Shinobi's raekor barb (last era). That raekor barb will still be better.
I don't like the way that some people think that an action rpg like Diablo 3 should have a 'support class' a 'dps class' etc - this game is fundamentally about killing monsters fast, and all classes should be able to. The fact that zdps crusader/wd and 2 dh feature in top grifts proves this point. And on PTR the DHs I know were actually holding back on a lightning build, I think, so the Wizards that showed in the Grift 60 clear that garnered so much attention are something of a ruse.
My issue is with the fact that even with a wizard with 1.5m sheet dps, 120% fire damage, a further 45% elite damage, I get out-dpsed quite easily by other classes. So much so that zdps crusaders will leave a Wizard, DH, WD group stating 'wizard useless dps' etc.
I have only ever played a wizard as it is the class that appeals to me, and Tal Rasha's is a step in the right direction, but I took a look at a nice ancient kridershot yesterday - look at the way the skills synergize in the DH class - it is simply much better. And APOC has been nerfed like crazy for wizards for a long time now. Does a raekor barb (top gear) face all kinds of resource management issues? No. Even a firebird wizard does, hence why cindercoat becomes so valuable.
To keep up with fast farming T6 I switch to an ancient Aetherwalker - a significant dps loss, and teleport then costs a lot of mana as well. To add mobility to a wizard then, we have to use our weapon slot. I mean, come on.
I just wanted to promote some discussion of the classes here too. In terms of a suggestion - I know that Blizzard are not balancing the game on group rift progression - fine, but to me (even in 2.2) there is still such an amazing disparity between the classes.