I prefer the new controller to the old. Subtle changes made a huge difference for me. The texture they added is nice. Much prefer the new d-pad.
While I thought the app setup was easy, I thought it was kind of overbearing. Not sure if there was a way to just do it manually. Seems to follow the Windows 10 philosophy where they want you to do things a certain way. Oh well, one time thing I guess. One issue on setup, it took a REALLY long time (maybe 5 minutes?) for mine to come up initially, just sat on the pulsing Xbox logo. Not sure what it was doing.
Only problems I have had:
Quick Resume will sometimes fail, cannot rely on this as a save.
Controller stops responding (still connected but not registering any inputs). Popping out the battery fixed it. Haven't had this happen since the last system update, hopefully it is fixed.