" Mb1, please elaborate more. I have heard them but not for hours on end. You mean, difficult as in tiring?"
Before I start, I need to be clear that I'm not bashing B&W. This is just my opinion along with some observations I've noticed over the years.
When you look at people who owned B&W speakers, you'll see that in most cases, they were one of the first pairs speakers someone buys. Its almost always past tense. I had B&W speakers, not have.
The main reason for this, is that B&W is a very exciting speaker to listen to. They have a quick, lively sound to them that really sucks people in. Once you have them for a while, the novelty wears off, and you begin to evaluate them in a more honest fashion. For most individuals, myself included, find that the high frequencies can be too much. Call it bright, sibilant, harsh... or whatever. Some people can tolerate it more than others. I even know some audiophiles that prefer this kind of sound. Its a judgment call that only you can make. If you still like them after an honest evaluation, then you should buy them. Your opinion is the only one that matters. My advice is to be cautious and not rush into a purchase. Also, my comments apply to both the aluminium and diamond tweerer's. They sound different, but I find both of them to be annoying.