One thing I don't like about Neverwinter is the limited action set, meaning that while you have access to X abilities in theory, you can only have Y of them on your action bar at any time, with Y being a much, much smaller number than X. I can just about tolerate the system in this game (though I'll yell "Gah! Need to change my bars around again!" occasionally), but I don't understand why this seems to be becoming the new trend in MMOs. Supposedly it encourages interesting decisions. I disagree with this for two reasons.
1) A lot of the time, these "interesting" decisions are actually no-brainers. As a Devoted Cleric, it's obvious that I'll need some dps abilities while I'm out questing, but want to have heals available when I'm running a dungeon. All the limited action set achieves is that it forces me into a lot of frantic UI fiddling every time I get a dungeon queue pop while I'm out in the world doing something else.
2) When there actually are interesting decisions to be made because ability A might work well on the first boss, but ability B might be better for the second one... the decision of whether to use A or B would still be there even if I could access all of my abilities! I suppose you could argue that it's more "meaningful" if it has to be either-or, but in my opinion that additional meaning is not worth the drawback of having to constantly adjust your UI.
In practice, what ends up happening to me at least, is that I just end up trying to eliminate the need for decisions (and the associated ability swapping) by building a set that has a little bit of everything, even if it isn't great for anything, and then never changing it again.