What I said in another thread about xcape:
It's pretty difficult to explain because I'm not fluent in english and I'm not an expert, I would say, compared to SB, sound is more laid back, a bit smooth sometimes, it's like SB sound has more shape, like it is in 3D and Xcape in 2D. After some more listening, I don't think highs are better than with mc5 and I noticed they sound a bit better with iAudio 9 (BBE Viva EQ) than with Fuze (Normal EQ).
mc5 are more balanced, have more accuracy and slightly more clarity than SB, but they sound a bit cold and flat, some people say they're realistic, to me they're not the best when listening to a pop/rock concert. Xcape is between both, less spacious, slightly warmer and more balanced than SB, but warmer, more engaging and less clear than mc5.