As with most things in beekeeping it depends on your personal preference on how you prefer to work and what use you are going to put them to.
Both have issues, use both but my personal preference is for the Paynes.
Good points on both.
Stackable brood,
14 x 12 eke
Top Feeder
Paynes
Integral Feeder is can be an issue, it can be taken out to make 8 or 7 frame nuc.
Roof too shallow, too cold.
Can be awkward to treat if using vaporiser.
Maisemore
Roof too shallow
Feeder bees can drown
Lip for frame rest delicate, I find better remove and put pvc angel on, also removes the squashing of bees issue when putting roof on.
If just want to put eke on with slab of fondant, it wont sit flat on top of frames without removing joint. (Its there so no gap when using it as 14 x12)
Treatment same as above.
Entrance can be awkward to fit Queen excluder as at bottom traditional wheel doesn't fit.
BS one does look interesting but I wont be trying it as doesn't suit the way I personally like to do things. Looking at the price including feeder and the thicker roof as a nuc it looks good price wise to the rest.
Both do a job, both winter bees well with a bit of manipulation.