For an extra 395.00 you get NEW castings, more power, and a lighter valve train. Plus the castings are thick and resist cracking unlike factory castings.
I like smaller valves in OEM castings because it's hard to get the bowls large enough to work with larger valves.
The RHS head has a nice large bowl that accomodates a 2.02 valve nicely. That's why I use that valve.