I was quite excited about ROS. Beta was fun, I loved the new Act and most of the changes made have been positive for the game overall.
That said, I was personally hoping for:
1) More legendary items, and better. Early beta was promising, with some really cool stuff like Demon Machine, Swami etc. having extremely cool effects and becoming very powerful with certain skills. However there didn't seem to be all that many items to find at the end of the day and far too many were seemingly placeholders.
Unfortunately, most of those 'placeholders' went live, and many of the crazier legendaries were nerfed to the ground or had affixes flat out removed.
While ROS was a big step up from D3V in this regard, the paucity of legendary items means that once again we have a few cookie cutter builds at the top tier revolving around the handful of Uber items in existence. Hopefully we see a lot more added in 2.1.
2) Class Balance. Yeah, balance is always going to be a tricky word in a game like this, and while I'd prefer a world where each class has multiple endgame viable builds with relative parity to each other - this is a tricky one.
However quite a few aspects of certain and a ton of underused skills need some love (and gear to encourage you to use them).
3) 3D Fixes! A personal one, but it's silly that this has not been fixed. Quite a few people like Diablo 3 in 3D and longstanding bugs were made worse in ROS, not better. There is a third party mod available that fixes all of them, but which is 'use at your own risk' sadly.
4) Big, social clans. While communities sort of fill the gap, I was looking forward to larger, more active clans. As it stands, playing off-peak in a clan with people from different timezones it's often quite lonely online.
5) A return to Diablo's darkness. I really do miss the grittiness, the occult symbols and the general uncanniness of the original games and while I do like the darker and grimmer feel of ROS, the game still feels too much like a slightly bloodier Sacred or Titan Quest than a real sequel to D2.
Overall though, ROS has been a big success to me and managed to take a lot of the bad taste that D3 left out of my mouth. I wouldn't call it perfect by any means, but 2.1 is looking very promising, and with some more legendaries on the way hopefully we will be in a good position soon.