Got mine first thing this morning...
While I only have 1 hour of use so far...
1) For some odd reason, the phone defaulted to the lowest screen brightness level during setup. To fix, I simply went into setup and put it in Auto brightness mode.
2) Feels a little warm to my ear during call. Could be just because of the heavy use over the first hour in setting it up.
4) It seems faster during web browsing than the SIII.
That's it for now.