I have a pair of B&W 804S's. Last year, I was looking to upgrade from my Magnum Dynalab MD-208 receiver. I listened critically to the integrated amp offerings from Musical Fidelity, Classe, Krell and McIntosh with my source material and a pair of 804S's. (I listen to a lot of opera and orchestral music, with complex instrumentation and wide dynamic swings, and that's what I used as source material to test equipment.)
I am no expert, and can only report my own impressions and purchasing decision. I was unimpressed with the Musical Fidelity integrated; in no way was it superior to the MD-208. The Krell was quite detailed, and in its way impressive, but sounded like hi-fi, not music. The Classe was, in my view, the worst of the group. I directly compared it with my MD-208, and was astonished at how much ambience and low-level information was missing in comparison. I had never been displeased with the Magnum Dynalab, but I came away even more pleased in comparison; it was much less expensive than the Classe, and a much more satisfactory product.
The McIntosh integrated was more to my liking than the MF, Krell or Classe. But ultimately, I revised my budget upward, and bought a McIntosh MC-402 power amp. I use the Magnum Dynalab as a preamp.
My focus in evaluating equipment was simple -- what sounds to me the most like real, live, unamplified music? By this standard, McIntosh was the clear winner among the solid-state products I auditioned, and going up the line from the integrated to the 400-wpc MC-402 made a substantial difference (the B&W's do benefit from power).
I was most taken with VTL power amps, but decided against them because I live in a warm climate (and they can double as space-heaters), I leave my amp on most of the time, and I dislike fussing with equipment. If you don't have those concerns (Paris is not warm most of the year), you may wish to consider tube equipment.