Fair point about the top end speed but until you reach 70mph arn't they fairly evenly matched may be wrong on this ? 
hehe.. well if blacky were here.. lol..
i really dunno.. ?parkers quote the 8v at 10 secs to 60, the 16v at 8 secs and the vr6 at 7.4.. ?
in reality.. i find myself creeping away from an 8v around 40.. ?beyond 50 i'm well ahead. this was before i learned how the car drives properly too.
the 16v is a bit crippled ?low down because of the traction control which is active under 25 mph.. (u cant turn it off.. vr6 has it too..). i
if i knew someone with an 8v could have some fun trying all this out

on the optimax thing.. the car runs loads better with it.. and fuel economy appears to be up a lil.. especially when pottering up the motorway at 75 ish.