To simplify things.

SMN scaling is around 30% increase per 20 iLvls

Other classes are are around 35% per 20 iLvls.

I've heard that bard is around 40% because they get so much from WD.

Since i70 where SMN started out equal with monk there will be about a 15% difference.

That equals about 80 DPS at i135.

You don't need that much damage in FCOB so SMN is still relative, unless you need to carry other players.