changing to the higher temp resistant fluid, and metal lines is for heat build up under high performance conditions. Brake fluid is brake fluid under normal operating conditions. It shouldn't make any difference in pedal feel. I think many are still running 10 yr old or better fluid. and over the years it breaks down and gets contaminated. I didn't completely change the fluid in our little N/A we are working on, and it seems to be fine. If it bleeds off again, it might be time for a complete drain. Trying to save the guy some money.