It depends on the room and the person. I have a friend with Martin Logan's and they sound great, however when off axis the SQ drops like a rock. IMO, if you have the choice between B&W, Sonus Faber and Martin Logan though, it's just a preference thing. What sounds best to you. At my Magnolia, I've had a sales rep state he liked the Sonus Faber's over the B&W's. I've also had another state he liked the B&W's over the Sonus Faber's, and didn't care for the Martin Logan's at all. And then you have Salk speakers that sound fantastic too. Quite honestly, if you had those choices, you really can't go wrong with any of them. Just demo them for yourself, and pick the one that sounds best to you. For me, I chose the B&W 805 Diamonds. Why? Because those are the size speakers that will work best in my room and they sounded fantastic when I demoed them. Yes, the B&W 800 Diamonds technically sound better, but they were out of my budget and also wouldn't even work in the room (way too big). So in short, first narrow down and select the speakers that work best in your room. Once you've done that, demo as many as you can to see which sounds best to you.
And sorry if I didn't sate this before, but my friend was using his ML in a 2.0 setup. I'm also using my B&W 805 Diamonds in 2.0. I'll later add a sub to cover the lower frequencies, but the 805's do a pretty dang good job of covering the lower frequencies for their size.