What people forget is the SLR chassis and monoque is all carbon fibre/ aluminium honeycombe, a big weight saving and strength advantage over anything else. The SLR shares a lot of the technology learnt from the McLaren F1. There maybe cars out there that would beat it 0-60 on a strip but remember it has been built to be driven on normal roads. There won't be many motors that would out drive it normally except the FI !!!
Dave