last time i check BLM doesn't build for sustained damage. BLM job is all about burst damage. (Titan Ex jail and add, for example). If you are playing BLM and hoping to get high sustained, I think you looking at the wrong class. BLM will never beat DRG/MNK/SMN on ST, they just doesn't build that way, but in a fight where a high burst or AoE (4+mobs)required, no other class come close to BLM.