I don't believe SS lines will do much at all unless your current lines are in really rough shape. I think a combo of the new master cylinder bleed correctly and the calipers made the pedal feel firmer. The initial bite of the HP+ was stronger but with the current setup on street pads it can be modulated better I think. I don't have repeated hard stops but have taken it to the mountains and there is no problem. I think the current street pads are rated for a peak of 800-900 which would take some serious beating to get to. I'm running ATE type 200 dot4 fluid. I will be 100% honest and say I knew going into this it was mainly a cosmetic add for street use. If you do actual tracking (which I may in the future) its a good upgrade.
Pete - 88 H22 4WS