Day 2? The build has been out for 15 hours at the time of this writing.....
I'm glad you're having a good time with it, though....
I'm about to get out the time machine and go back to the prod ring. My phone was plugged in overnight, and when I woke up this morning, it was at 89% and warm. Using it while plugged in, for about 45 minutes, it was down to 60%. That's just facebook, news, Dilbert.app - you know, the morning grind. Then I decided to just run it dead. Unplugged it, and 15 minutes of YouTube and it asked me if I wanted the battery saver mode on. Nope. Another 10 minutes of YouTube (YouTube using MetroTube, that is), and it shut off.
I threw it into the freezer for about 20 minutes, and now it's charging. Once I get it charged, I'll start the rollback process to 8.1, and then I'll bring it up to the 10586 prod ring. I'll be a bit more cautious about Threshold builds, and won't be the first one installing it the next go-around.