@Salman
are you saying it wouldnt be fair, or are you asking me? 
I know the SL BS and Cali have two completely different characters, but as far as I can think right now, the SL BS is the only hardtop convertible that can perform like the California.
0-100 in under 4 seconds, and top speed around 310-320 for both of them.
The California is a very elegant car, featuring a smaller but characterful high-revving V8. It's smaller, lighter, nimbler on the track, and a good cruiser away from it.
The SL is like its evil stepbrother, and with all its body fat it provides the same benefits on and off the track, but does it with sheer muscle from its Twin Turbo V12, and its brutish looks.
Ignoring their prices:P, I'd say they're very evenly matched. They just happen to do the same things in two completely different ways.
@tevion,
I dont know if it's the wheels, but the California looks H.A.W.T in White and Silver.