batt life (incl strange readings that seemed to go down then up without actually charging the phone) have been occurring the entire time since i was on pb1. along with the phone running hot at times when i wasn't using it. i'll see if things get back to "normal" after some time. right now the lag is 5-20 seconds to do just about anything on the phone.
What hardware are you on?
I won't put iOS11 on my phone until PB3 or 4 (and after I've figured out replacements for the few 32bit apps that won't run on 11), but I just put PB2 on my iPad and it's running quite well. Every once in a while I notice an animation jitter, but that's rare, and pretty much all other actions are as responsive as I would want them to be.