@wrcompositi - I had a Vittoria Diamante Pro Radiale on my front wheel and all I can say that I won't be buying those again. Lasted less than 700km, much sooner than my GP4000s which I had installed on my rear wheel 4-5 months earlier than the Diamante. The GP4000s is still strong and not showing any sign to slow down.
The rubber is really thin on the Diamante, showed thread really quick and I had a slash on the sidewall. With Diamante Pro Light being lighter, I don't think it is a better product.
These sure feel nice, but they're not worth their price. My rear tire only lasted 1000 km and I've had countless punctures, both at rear and front tire. And they don't feel as secure as the gp4000s on wet roads.
If you go the Vittoria route, it's Open Corsa or tubulars IMO.