I work very closely with MB ad have got an SL65, and i have to say that the performance is astonishing. I thought that the SL would be more of a GT car than an out an out performance car, but it manages to do both with ease.
Last week, I drove the 3rd ever SLR to be produced. I imagined it to be more of super car, but it is actually quite luxuriouse. However, the two cars should not be compared.
Even though the SLR only has a 5.5 V8, this is the more flexible engine than the V12.
If you look at MB's new line up, the 5.5 is going to be put in the C class and the SLK, but these will only produce around 350bhp, whereas the SLR produces nearly twice that. There is potential to squeze a bit more from the 5.5, but the V12 was chosen for the new AMG venture because of its smoothness.
I have however just watched the new Porsche Carrara GT out perform the Enzo and SLR, and am trying to get my hands on one...