Class D amps,bang for your buck ones

I haven't compared the W4S to any Rotels so I can't comment to that.
Compared to the Mcintosh MC352, particularly on the Dun's the W4S sounded more aggressive in the hi mids. I would in no way call them "loser". My impression is that they are very fast accurate amps. Tight would be the adjective I would be more inclined to use. They sound great on the B&W 801's in my studio.

The Mac on the other sounds great on the Dun's, but is a bit wooly on the 801's.

Another vote for the Onkyo A-9555. I've had mine for 1-1/2 years. It is very fast and clean, yet not etched or irritating. The speed and low noise floor enable me to hear much more continuity to the music and bloom and fade in the individual notes. It's very dynamic, both for slam and for nuance. At its list price of $799 it's a good value; at its typical <$550 street price it's ridiculously good.

Only caveats:
1) It doesn't have pre-outs. You have to use it as an integrated unit. Fortunately it makes about 85/170 watts into 8/4 ohms and sounds more powerful than that with lots of slam and bass extension.
2) The built-in phono preamp is decent, but eventually you'll want at least a Cambridge 640P to add some slam and dynamics to LPs
3) The speaker terminals are those wimpy ones that accept only bare wire or bananas. The amp sounds so good this is a minor inconvenience. I'm using locking bananas and they're just as secure as spades and a lot easier to use.
4) You'll get a jump in sound quality with an aftermarket cord. Switching amps are pickier about the AC quality.
5) Must give it 100 hour break in or you'll think the A-9555 enthusiasts are deaf or masochistic.

Its low level resolution is very nice; it even warmed up my CDs.

Both TAS and Stereophile gave it positive reviews. S'phile gave it a class C recommended rating; based on the other class C selections, I'd say the A-9555 is borderline class B.

I just ordered the class D audio amp (600w version):

http://classdaudio.com/index.php

Jtwrace, the ClassD amps look very interesting as they utilize some fairly novel technologies from TI. What will you be using for power supply. .. unless I'm wrong, they seem to require an external PS. Guido

No external power supply required if you buy one of the kits. Just an power cable. I keep telling myself to try the 125 watt version.