I own a modified Audi S4 (chipped to 307 hp; 366 lb/ft; 3400 lbs), but yesterday drove a '00 M5. The M5 belied its size and handled really well for a 4000 lb vehicle. After reading all the gushing magazine reports, I was very surprised that the M5 didn't seem as torquey nor did it seem to accelerate any faster, if at all, than the modified S4.
Strictly from an acceleration and engine standpoint, are there others out there with similar or contradictory experience?