I am using an SM-910F with the German lollipop ROM (5.0.1)
Things are smooth and good. Except for a couple of issues.
1. 'Emergency Calls Only' keeps happening. Switching on flight mode and then off again solves the problem.
2. My Contacts app keeps crashing when I open it. Works on the 3rd or 4th try.
3. I dislike the new Slow-mo mode, and editing. Luckily the slow mo video gets uploaded to dropbox so I can edit it in Adobe Premiere
4. Battery life is not too good. Given, I think I am one that screws up a battery good and proper. When it hits 60% i panic and start charging it again.
5. Popup notifications are a frustration. Especially when the whatsapp groups start chatting. Then you have this massive white bar popping up after every message, probably about 2cm tall, from the top of the screen.
6. Recent apps button still seems to lag.
Other than those issues, I am very happy with the software. And the phone. Pictures are gorgeous, apps run fast, screen is beautiful, size is good.
Here is one of the better pictures I took over the weekend.
http://i.imgur.com/44d51it.jpg