As others have mentioned I'm pretty happy with the new update for the time being. I really like the new UI, but I too wish it was more consistent throughout the different menus, similar to Plex.
On the downside, it seems slower to me. Whenever I try to switch between menus (TV Shows to Movies, Music, etc.) I experience a 5-10 second delay. After the initial delay the AppleTV becomes very responsive, but I hate waiting for it to play catchup every time. The only other problem I've noticed is how much longer it takes to load my shared libraries. Loading my libraries takes 2-3 times longer than it did before the update. Hopefully 3.0.1 or whatever isn't too far away.