From what I have looked at, the steel braided brake lines make no performance difference. They are just rubber hoses, wrapped in SS. It is more of a protection thing?
The braided lines make a difference for sure. When you press the pedal down with the normal rubber lines, some of that hydraulic energy is being spent in the wrong direction because it is being used to press outwards on the lines causing them to bulge. This energy is totally wasted. The intent of stainless braided lines is to keep the rubber from bulging out as much so more energy is directed to the intended target being the brake piston. The stainless also no doubt provides an anti abrasion factor as well, but I think the lines are protected enough that that wouldn't be much of an issue anyway.Frankly I have the lines from independent and the glitzy colored hard plastic coating they have doesn't last more than a year or two. I had to have one of mine replaced by a local hydraulic line manufacturing company which made me a far superior replacement line that is actually DOT rated. The plastic coating they used was guaranteed not to crack off like the indy4x4 set. The cost was approximately the same. BTW mine are for sale if anyones interested.