I put SS lines on the front of my 03 mustang, but did so at the same time as a cobra front brake conversion (from 10.9" rotor to a 12.9" rotor, and better caliper and pads as well)
I will say the pedal feel is much firmer, but that could also be attributed to the bigger brakes. Overall, if relatively cheap I like them, especially if you dog on the car, because they can sustain more heat IMO, and offer a good excuse to do a full break fluid flush and add something more high performance.
However, I would not pay more than ~$200 for parts IMO. Past that, it isn't worth it to me.