Dave - I wonder if the Martin Logans you heard were not set up properly, one of the things I love about my ML SL3 is the soundstage, they very precisely locate the instruments. I have them 5 feet from the rear wall and 4 feet from the side wall, and toed in so they face directly to the listening position, about 7 feet away. If you are in the sweet spot the Martin Logans disappear.
I have a 2nd system with Sonus Faber Signums (which I guess might be more comparable to the B&W). The Martin Logans do better on imaging than do the Signums, and the midrange might also be better on the ML, they are outstanding for jazz, folk music and string quartets. But overall I prefer the Signums to the ML, it seems to me that the SF Signums have a more natural and musical sound and also better integration of the base, while the ML have the problem of the directionality and small sweet spot. For "dedicated" listening in the sweet spot I might lean more to the ML, if you are moving around the room or have guests, or listen to rock I'd recommend the cone speakers.
I have a 2nd system with Sonus Faber Signums (which I guess might be more comparable to the B&W). The Martin Logans do better on imaging than do the Signums, and the midrange might also be better on the ML, they are outstanding for jazz, folk music and string quartets. But overall I prefer the Signums to the ML, it seems to me that the SF Signums have a more natural and musical sound and also better integration of the base, while the ML have the problem of the directionality and small sweet spot. For "dedicated" listening in the sweet spot I might lean more to the ML, if you are moving around the room or have guests, or listen to rock I'd recommend the cone speakers.