I've owned three RKCs, a SG and an Ultra. If I'm buying a bike to keep pretty much stock, I'll get the SG or Ultra. If I'm buying one to customize, I'll get the RK. Right now I'm looking for a RKC.
Normally I prefer SG's over RK's ... but NOT in this case. I just plain don't like the overall look of this SG - esp. hate those front wheels that look like an 1800's bicycle ... But as my dead departed mother used to say "What a dull world this would be if we all liked the same thing."