You are comparing a standard AMG with a modded Cossie. The car below is a AMG with 700bhp/700ft-lb it would simply have disappeared like a rat up a drain. Cars appear fast when they have the beating of the other guy.
The picture was taken at a UK Topspeed event that Merc came 6th a very fast car.
If you look carefully a White Saff Cosworth rear end can be seen in the crowd of cars .