Had it on my iPhone 4S and the installation was the smoothest so far. Running it on your primary phone could be a bit risky, depends on how you use it. I use Podcasts app a lot and having that completely broken is unacceptable to me. I'm going to revert back to iOS6 for now until Beta 3 or higher comes out. Also, I hate the Home screen and the icons...just so terrible of a job from Ive and his team.