I played a BKSOR Pro and a BKSOR Premium yesterday at PATZ (thanks to Trent from Tilt Amusements). I liked the Pro which I played first, but I loved the Premium which I played second. On the Premium, I was able to start the lower playfield multiball then lock a third ball in the upper playfield lock and stack both of the multiballs together, which lead to a super fun and furious 6 ball multiball. Stacking the upper and lower playfield multiballs was such a fun challenge I think I'm firmly in the Premium or LE camp when it comes to this title.