The R might be there merely because the North American HSDPA bands for rogers are 850/1900 and not the ones you would normally find on the phone. I know of at least one user on samdroid.net who flashed his rogers galaxy spica without a problem. beyond that, the hardware itself should all be the same, and thus there shouldn't be any harm in flashing any official firmware onto any phone.
It's kinda like how its the same android firmware for a google nexus one regardless of where the phone is.
Thx I got it to work yesterday and I am very happy I upgraded. No more lag on games and phone seems faster. When I go to the about screen now the model doesn't have the R their anymore, but I don't really care about it everything still works. The upgrade though is well worth it.