Just a few major points i have seen so far. Battery life on the 9.7 ipad pro is not great on beta 2. And I have also had issues connecting my phone to my VW bluetooth system. Automatically places a call to "my phone number" on the stereo but doesn't show up on the phone. The only way to stop it is to disconnect the phone from bluetooth connection to the car.
For those commenting on the watchOS beta, be glad that Apple doesn't do public betas on this one, the battery life on beta 2 on that is HORRIBLE. Drained completely in 8 hours. Going to try a reset and give it another shot, but anyone who has access should stay away from the second beta for watchOS 3 if you haven't loaded it already.