I've auditioned the Firebirds and WP7s at length, and the B&Ws for a briefer period. All are excellent speakers and your preference will definitely come down to taste. All three are solid companies, with Wilson and B&W having even longer histories, important points to consider with any purchase. I ended up purchasing the JM Lab Nova Utopias which I found created a more lifelike listening experience for me. That said, all of the speakers you list will require careful matching of components and that choice can easily make or break the magic or lack of it you hear. I recall first hearing the Nova Utopias with BAT gear (very fine stuff, no doubt) but to my ears this combo created signifcant discontinuity of the berryllium tweeter and the rest of the drivers. I quickly dismissed the speakers only to hear them several months later with Burmester gear and being floored by the seamless convincing picture. As stated by the others here, listen to each as optimally set up as possible. I would recommend adding to your list, however, JM Labs Nova Utopias, Verity Audio Sarastros, the Von Schweikert VR7se, and potentially the Dali Megalines.
Good luck and enjoy. Half the fun is the search.
Sam
Good luck and enjoy. Half the fun is the search.
Sam