I've played Diablo since the day the first one came out. I really loved D2, hated D3 at first until they fixed a whole bunch of things (looking at you real money AH) and have just completed the main campaign in D4.
I do miss my superspeed WW barb from D3, I mean just absolutely blitzing a dungeon in under 20 seconds was always a ton of fun, but I've really come to enjoy the world building and story of D4 a lot. The mechanics are definitely pretty different in some aspects but I find that being forced to slow down and just actually enjoy the world is pretty great.
Looking forward to capstones, whispers, etc. and getting further into it. Are there issues with it? Sure, of course there are, but I think that things can only go up from here!
Really started playing in D3 so the slower pace of D4 is a bit jarring. Overall though I'm glad to be playing a new Diablo and looking forward to trying out different builds once I level up more.