Went from Shim to Camp....
Just different, that's all. I really think it's up to the user.

For me:

Veloce is a more mechanical shift....it clicks in and you 'feel' it. Ultegra is softer. smooter....less feedback in the hand when shifting.

I will say that I felt what many others have written about the hoods too....at first when going from Ultegra to Campy those thumbs shifters seemed really strange. Now I can't imagine it any other way.