Screen is great, though as people mentioned, it has some strange lines when viewing dark greys in low light.
Phone calls and texts work perfectly for me. Bigger screen has been great for typing.
I'm stock and rooted, and the performance has been great for me. It can handle just about everything I throw at it w/o any lag at all. I'm sure it'll be good for gaming, too. The one thing I'd look out for is that some games are not compatible on our devices for some reason. I tried to purchase Asphalt during the 10c sale, and it was only compatible w/ a GS2 (my previous phone), but not the SR.
As for issues: The screen issue mentioned above, and on mine, sometimes bluetooth doesn't turn on (though it's been awhile since that's happened).