I own both.
The BFP have much better sound, spatial audio and a few little bells and whistles that come with the H-1 chip (although the BSBs emulate some of that via firmware). I find the BFP stay in my ears way better when working out. My BSBs have now become my "sitting around the house listening to music/podcasts" buds and my BFPs are my outside/gym go-tos.
Nothing wrong with the BSBs, but the BFPs are literally the best-sounding earbuds I've ever used.