For me, it's not about the .8 seconds quicker to 60 or the 2 mph trap speed, or the 1 second faster around a road course. Does that REALLY matter? Most of us are not pro drivers and simply will never drive any car we own to within a inch of it's limits. We'll reach our level of incompetence WAY before that. I've owned Mustangs, Firebirds, Trans Ams, Dodge Daytona (gag... sorry), a e36 M3, e46 330ci, '08 M Coupe, a 135i, and now have an e93 M3.
I pick my cars for reasons other than strictly HP numbers of 0-60 times. Sure, I don't want a dog, but the difference of less than a second to 60 is insignificant to me. I picked the M3 because of the styling, the looks, the handling, the interior, the sound, and the rarity (in addition to the HP). It's the whole package for me. I don't think any American muscle car can match the overall package. I don't mind paying more - I don't buy new anyways. There will always be a car that's faster out there. I'm ecstatic with my M3.