Yes, I guess Krell, YBA, Levinson, SimAudio would be "leagues ahead" of Denon. In the same way Wilson Audio speakers would be leagues ahead of Paradigm, NHT, or, dare I say it, even Axiom. But who has $100,000 to blow on a pair of speakers? The point is that you'll eventually hit a point of marginal returns--where a perceptible increase in sound quality will require you to spend not hundreds, but thousands of dollars--the area of hi-fi reserved for golden-ears and professionals, NOT necesarily for home audio. Anyone can name high priced brands, but only few can or should own them.
I agree with Ian, at this point and for this audience (i.e. the average consumer) the sonic differences between amplifiers is fairly small. But by all means, if you are one of those with the ears and the cash to demand better sounding equipment, go for it. Just remember, spending more on quality speakers (moving up in the line from m60s to m80s) will probably yield a much more perceptible increase in sound quality than going overboard with the amp. Take home note: don't go overkill with the amps because you don't need to, just make sure it will drive your speakers without clipping, shutting off, overheating, and at the volumes you like to listen at.
