One of the very few (if not the only one) restaurants on the strip where the Vegas location is a LOT better than the one in NYC. Scarpetta LV is light years ahead of its namesake in Manhattan's Meatpacking district.
The service is, without a question, much better here than in NYC and so was the food. Scarpetta NYC, on the other hand, has a quirkier, much more interesting wine list featuring Italian wines exclusively.
So, I guess you'd have to visit both locations and decide for yourself.