Improved grip stippling.
Eliminated the beavertail.
Improved slide stop.
Improved (PC) trigger--(lighter?) with improved reset--audible & tactile.
Almost forward slide serrations.
5" version available standard, with new tactile Loaded Chamber Indicator (LCI ) [Looks like it might interfere with mounting a red dot sight.]
Ambi metal mag release.
Different ejection port machining.
Steel insert in polymer dust cover to stiffen frame.
Lightened slide (narrower front top profile).
4th backstrap choice.
"Windows" in dust cover that are backed internally by the new steel skeleton, so not really windows that would allow **** into gun. Basically cosmetic, perhaps to quickly differentiate V2 visually.
Backwards compatible with mags, holsters, sights.
Different name for the same finish?

Anything else?