I, once again, had to go back to 7.1.2. Every beta release I get that hope that "this is the one that I can finally use to test my apps". Every time I load up the latest beta on my 5c, the bugs start as soon as it asks you for your passcode. The number pad will not minimize down so I can push "get started" to go to the home screen.
Once I reboot, I can get to the home screen, but the problems just escalate from there. My 2012 MBA with 10.10 says "cannot connect" when trying out continuity. No matter who I'm looking at in the contacts, it keeps the same picture. I still have to re-enter my iCloud user/pass every time I reboot the phone. It still has trouble holding my preference for "every 4 hours" passcode entry instead of immediately. Unable to place facetime audio calls about 25% of the time. About 50% of the time, I can't hang up a call... as in the red button at the bottom simply doesn't respond. I have to awkwardly ask the other person to hang up first. I have, at least, 50 or more purchases on my iCloud account, but the app store tells me "no purchases" under my account (they are there in iOS7). All issues have been reported to Apple using the bug reporter and flagged as duplicate.
Thus, I'm finished with the iOS8 betas from here on and will wait for GM.