Thanks for the review. I picked up a Sonos Move and a B&W Formation Flex for a casual bedroom setup. My opinion is tonally the Sonos is extremely pleasant while the B&W has the standard zingy sound you get from B&W speakers (it has the 600 series tweeter supposedly). That said the bass region sounds extremely tubby and bloated on the Sonos. It's got a smaller woofer than the Formation Flex but feels like it's playing at least 10-15hz lower in room.
I find both of these kind of unbearable to listen to anything higher than ~70db listening level. With the Sonos, the boomy and tubby sounding bass just dominates the sound, and with the B&W I can't stand the rising treble. But if you put a gun to my head I would rather listen to the Sonos.
That said I'm surprised just how wide the Sonos dispersion is. While it's no Homepod with 8 tweeters, with it's a single downward firing tweeter but feels like its multiple tweeters in that it sounds almost omnidirectional, and the directivity graph really helps show how this is happening with the dispersion widening below 2.5K. The B&Ws are very directional, which in some ways is a good thing, because otherwise the treble response would be a real problem, but it does make it sound very small. IMO the Sonos in mono sounds bigger image-wise than a stereo pair of the Flex, which is interesting.
Did you do the TruePlay autoEQ on the Move? It generally fixes the bass, at least with my SONOS Ones. I think the Move now has Auto TruePlay via a recent firmware update.