Typical Characteristics of a McIntosh / B&W system

I've owned high end McIntosh (always receivers, not separates) and B&W speakers before. Sold my last setup 4 years ago when I moved to a small apartment.

I'm finally in a place where I have a listening room, so I recently bought the McIntosh 6700 receiver and B&W PM1's. It sounded great in the store, but sounds mostly like crap at my place. It's WAY too bright. Sounds decent at low volumes, but if I turn up to normal listening levels or, heaven forbid I go to 11, it becomes unlistenable.

I'm sure my room plays some factor as I haven't treated it yet, but my $450 AudioEngine's sound amazing in the room and this $12K+ setup sounds like crap.

I will say that when I auditioned the McIntosh/B&W's in the store, I realize in hindsight that I listened to a lot of acoustic-y music. Even at home, the set up does ok with that style. But everything else sounds pretty crappy.

Perhaps my ears have gotten overly sensitive to music on the brighter side. Or maybe this receiver or McIntosh in general are skewing their sound to be overly bright/revealing/clean etc.

Any opinions on this? Are McIntosh/B&W setups known to be overly bright?