There is no absolute performance difference...5-10HP could be gained or lost just by variables. In fact, Car and Driver also got a 5.9 second run from a 04 EX V6 6MT coupe. The car may react to throttle differently, or have a bit more low end, or other things. But when push comes to shove, the 04 and 06 did the same 0-60 run, but one was a coupe and one was a sedan. They weigh a difference of 73 lbs, which would at most result in a difference of 0.1 seconds.
