Just thought I'd give a heads up and let people know my experiences.
The OS is fantastic. A genuine quantum leap over iOS6 with regards to functionality - and although I was previously dubious regarding the visual style, it's really starting to grow on me. That all said, this being a beta we can all expect there to be problems and bugs along the way and obviously anyone who does install this does so at their own risk. You may want to think twice if facetime, imessage, and push notifications from third party apps are a lifeline for you...
Specifically I've found that I'm encountering a message when loading up apps which use push notifications:
Connect to iTunes to Use Push Notifications
There are also issues with facetime and imessage. Facetime asks to check network connection when you try to sign in and turn it on.
I've attempted to resolve this by wiping clean and restoring from a local backup. I didn't think it would work but figured it was worth a try. If anyone else has suggestions for resolving this I'll certainly give it a go.
Just thought I'd warn anyone who was considering upgrading.