The catch-up mechanic is real, yo.
I decided to level an alt over the long weekend. I really like what they've done with the animations and effects for melee shaman. Lots of storm noises and bursts. I went from having AP items give 100-175 each to BILLIONS. OK, then. All the traits, all at once. (*)
There was definitely the challenge of suddenly facing 110 mobs with sub-110 gear; fortunately I had a lot of the 880 tokens so was able to swap out all but two gear pieces. Weapons still lag because empty sockets but that'll get fixed once I get to the point I can buy 910s.
I found myself intensely disliking the shaman solo questline. It's a LOT of flying over boring empty zones and then pointless fights filled with annoying trash. I can see how it's conceptually and story-wise appropriate and possibly interesting but the annoyance factor outweighed that for me by a lot.
(*) From this perspective I'm kind of sad that the weapon traits end up all being rolled in at once and all I'm left to do is grind AP for an occasional stat click. I feel like the artifact trees were one of the best things about this expansion, marred by the mechanics of AK (ptui, good riddance) and the idiotic decision to make everything into unique non-stackable tokens that require constant spec-switching. If AP had been implemented as a pool that you could allocate to things that enhance your play style or that helped with particular encounters I think it would have been more fun and less homogeneous. And, frankly, less boring.