I can't think of a single part that would interchange if you're talkin' hard parts.
Seriously, the RC is committed. In the riding position, the way the engine makes it's power, and the way the suspension works.
It's a pretty firm bike with stiff front springs,(1.05 stock) and plenty of compression. Steers quite nicely though despite it's weight. Solid as a rock at speed.
Lots of power but wants to be revved, kinda like an inline. They run quite hot too. Also in my opinion they're crap if you ever ride in town or take a pillion. Not what the RC is really for so you get what you got.
The SuperHawk makes a great street bike (except for the mileage). A little softer and more upright. I would also bet the Hawk makes more power than the RC up to about 6k. That's good for the street. It doesn't have the killer looks or pedigree though. The RC won the World Superbike and AMA championships as well as the 8 Hours of Suzuka. Well, I guess the riders won the races but you know what I mean.