I did the update on my husband's Epic - it was terrible. The biggest problem, at first, was blinking keyboard, it wouldn't sign into Google. Rebooted 3 times and that quit, got everything on - then the phone's ring
was probably on a scale of 1 out of 10.
Nothing fixed it - called Advanced Tech Support - this is one of their "issues" which I call a problem.
Only fix is (1) Service Center to downgrade, (2) use Odin and bricked stickie, or (3) root and flash.
He will not allow me to "break" his phone (I'm running rooted Midnight) and has listened to me cuss and mutter too much!!! So luckily I could Odin back and put things as was.
So before you upgrade, remember a phone is a phone and it should ring - other "issues" are annoying, but it has to ring!!
And to be honest, casual users like him can't tell the difference, so save yourself the headache of potential problems if you aren't going to use some of the new bells and whistles and wait till they are sure everything is fixed.