It comes down to preferences. If you prefer SxS to OU, like me, a BSS is better than any Superposed ever made, IF you are buying it to shoot rather than brag, collect, or show off. If you prefer stacked barrels, then the reverse is true.
As far as SxSs in general go, my BSS Sporter 20 is my favorite gun. It is not a featherweight, but neither am I. I love how it shoots for me.