Let me get this straight. You say the Road King 103 you rented was hotter to ride than the R3. And that is why you sold your Street Glide because it was too hot to ride? Have you ever rode an R3? I can tell you right now, living in the HOT So Ca desert area, my 07 Street Glide that I sold and my wife's 05 Road King that she rides, were and are WAY cooler than my 011 R3T to ride in traffic!
The heat the R3 radiator puts off is like an oven in front of you on hot days! Great in the winter. That was the first thing I noticed about the bike when I rode it home 130 miles from the dealer in Los Angeles. Unless you live in a cold/cool area, I don't think anyone would say the R3 is a cooler bike, engine heat wise, to ride than the Harley. Cool bike to ride, but a hot sucker in the heat!
I only road the R3 for a weekend but it was hot and it really didn't bother me as much as the RK.