I play Arms/Prot, Havoc/Vengeance, Ret/Prot/Holy, and WW monk.
I think Demon Hunter is in a good spot overall, I miss the artifact ability for both specs but overall they feel fluid and satisfying. Vengeance overall is the most unique tank spec I'd say, with Sigils and the ability to fly all over the place for mob control and stacking.
Arms and Prot are both pretty satisfying to play, Fury sucks, hate the spec.
Paladins are in a decent enough spot, I feel like Ret is a bit too simplistic but in PvP all the utility they bring makes them a blast to play.
WW Monk honestly isn't much fun. The GCD change really messes with that class.
Overall I'd say I'm satisfied with overall class design, at least for the classes I play. I used to play Shaman but after Legion I shelved it, Blizzard will never get Shaman the proper attention they deserve.