I've currently got this, the Senn Momentum, and the Sony MDR-1R in-house. Sonically I think the PSB is pretty fabulous and is beating out the other two, but I have to say that I have my concerns about construction and durability. And they're BIG. Sheesh! Purely from a design and comfort perspective the Momentum is the clear winner here IMO, but the M4U1 sure does sound sweet. Straight out of my Rockboxed iPod 5G playing FLAC it's very nice indeed. The bulky, plastic "cavemannishness" of them are kind of turning me off though... Does anyone else have the PSB? Care to weigh in?