I paid 450€ only several weeks ago and I'm a happy owner.
It's featured by a Tube preamp & a small Tube poweramp followed by a mosfet power amp. The Quadrumatrix-4-position knob changes between two different electrical designs of the tubepreamp and again these combined with the poweramp valve. The mosfet-poweramp has got 600 watts, an is loud enough for everything.
The input stage ist not too sensitive, for getting a crunchy tube sound and an bit of compression, I have to set the gain to max. If you like your sound warm and crunchy and not too slim, you may enjoy the versatility offered by the Quadrumatrix (within those borders of the warwick voicing). I do.
Warwick's amp sound has to be described as warm and not slim in general, some people noticed difficulties cutting through the band mix in some cases caused by that sound.
Muddiness is critisised by some, i think, that is caused by using Warwick cabs. The amp is not voiced as trebleless as an ashdown amp.
http://www.warwickbass.com/media/man.../QuadVI_DE.pdf http://www.warwickbass.com/media/man..._diagramS2.pdf