"I have lots of people come in on the Metric Cruisers and the number one request is "Make it sound like a Harley". "
Who cares about metrics. I don't want a Harley and I don't want a Japanese imitation of one. Now lets see Harley beat the Japanese at their game, in any other class of bikes. I don't think they could, even if they wanted to.
A regular can always do one thing sitting still that a regular Japanese bike does not do.
Attract attention. (particularly of the ladies)
It is no different than the kid with the 4.5 sec. souped up honda vs the owner of a factory [insert name of sports car here porshe/corvette/ferrari/lotus]
NOBODY travels faster than perception.