Nope. It isn't just you. I've had the worst battery life ever from Beta 5. Every time I install a new beta, I set it up as a new watch after unpairing and repairing. I usually test under a base load with no external applications running. In fact, I use only the watch face itself. Yestereday, my watch went dead from a full charge to 0 in slightly more than 4 hours. I recharged it, and it went dead again after 4.5 hours. This morning I unpaired it, and reinstalled the Beta from scratch. Down 30% in 90 minutes with nothing running except the watch face.