I too encountered issues with Google Play Services, so it was very helpful to have seen the resolution to that here prior to upgrading. I was forced to uninstall/re-install updates twice though. After the first time, Play Services would repeatedly crash, especially after a reboot. It took removing it again, clearing cache (to be safe) and rebooting before the update worked reliably.
I ran into another issue which some might find helpful. I have an Asus ZenWatch and after the update it refused to connect or pair even though both devices saw each other as being available. Nothing worked until I did a full reset on the watch, then it was finally able to connect. Fortunately that's easy to do as it's not like resetting a phone and dealing with tons of app installs. It's done in two minutes.
Everything else has been smooth for me and I haven't noticed much if any difference in battery life. I've stayed on using Nova Prime for my launcher and SwiftKey keyboard, so I haven't seen any of the "stock" touchwiz changes. The updates to the dialer and contacts don't really bother me. I very much like most of the other Lollipop changes, but I knew what to (mostly) expect from my Nexus 7 updates.
The one thing I'm really disliking is the loss of being able to use SkipLock. I loved that application and its ability to easily handle locking/unlocking my device based on trusted bluetooth devices and WiFi networks. Yes, I know about "Smart Lock" and how to activate it in TouchWiz... already done it. IMO it completely sucks compared to SkipLock. The "trusted places" function is totally unreliable. No option to add trusted WiFi networks. In my use, it pales in comparison and the only saving grace is that I have my ZenWatch on most of the time as a trusted device. Otherwise, I'd be pretty pissed at the loss in overall functionality and reliability.