The theory is, it's the somewhat flexible stock material hose portion of the pressurized brake system that flexes & contributes the biggest portion of "squish" feeling that's still there in a properly bleed/no air in the fluid, system.
It makes sense that swapping in the less flexible aftermarket lines would improve pedal feel regardless of antilock/no antilock. I've just heard enough folks tell me the benefits weren't as great w/ antilock, so I asked Fermenator. I believe the man that's done the mod & seen the results.
What brand of ss lines did you use? Price, etc.?
I haven't looked that closely at the condition of my stock lines, but will consider going to the ss lines if the cost is reasonable. My experience in performance cars was very good.