The Bose set has a hole in their frequency response: Acoustimas bass module rolls off around 200Hz, satellites pick up around 260Hz.
Even if the satellites did go lower to close that gap, 200Hz is still too high of a crossover point. By that point, frequencies have become localizable and you'll hear male vocals coming from the bass module.
So even though Bose's marketing says you can hide the bass module behind your sofa with no ill effects, that's really not true (unless you want your wife complaining "honey, the couch is talking to us again").
By comparison to the Bose satellites, the B&W M1 goes down below 80Hz, so you'll be able to cross over to a subwoofer below male vocals and below where the sub will localizable. That alone makes your choice a no-brainer.