Apparently, there's a difference of opinion concerning whether or not certain B&W speakers lack smoothness in the treble and can become too bright and fatiguing for some. I've never listened to a pair long enough to have an opinion but I have, over the past 30 or so years, auditioned many B&W speakers in the mid to top model ranges.
As I recall, I never purchased a pair due to my perceptions that they generally sounded a bit lean in the bass and somewhat jacked in the treble.
Not a combo I prefer but traits I always remember believing could be remedied through room treatments and perhaps a pair of properly positioned and configured subs.
These were remedies I didn't want to invest in or think should be necessary, at the time, due to the already fairly expensive price of the pair of speakers. But I still believe that the sound of most B&W speakers, as well as the sound of the vast majority of other speakers, can be significantly improved through appropriate room treatments, mainly at the first side wall reflection points and the front wall behind the speakers, as well as a pair or more of subs that are properly positioned and configured.
Tim