We're actually starting to get people that are more concerned with leaving the dynamics in stuff we're mastering. Most still want it crushed though... I would agree that a portion of it is just hypercompression and not distortion but for a handful of mastering folks a "trick" they pull out of the bag is called clipping. It's basically distorting (chopping off the sample at digital "0")the signal but not to the point where it's heard easily or at all.... I'd like to note that this almost always is coming at the request of the artist, prodeucer, record company, etc. Mastering guys would LOVE to leave the dynamics as much as possible..... Also, I can't say that I love the sound of John Mayers albums. I do hear some light distortion and some heavy compression.... An album I think sounds great and isn't overcompressed is Damien Rice - "o"..... That's my 2 cents.

Paul Elliott
Head Mastering Engineer
The Soundlab @ Disc Makers