If you are under the car a lot and pay close attention, then stainless braided lines are a great idea. If you aren’t paying close attention to them, you might consider getting one that has an external sheathing. The stainless braid collects road crud and can a abrade the internal soft lines. This is no big deal on a car you pay a lot of attention to like a race car, swapping brake lines frequently, but not so great on a “set it and forget it” car like many people have for street cars.

I fitted goodridge phantom braided lines to my car , ( never seen a set for Porsche where the braids weren't sheathed but they must be out there ) , these won't give much of a performance improvement to a 996 as they would in an older car . But it's nice that all the fittings are also stainless so wont corrode making future brake work much more pleasant .
if you have to change the lines anyway it's worth doing for improved longevity but I wouldn't make it a huge priority .
They weren't much more money than oem . Pelican has a few options . I chose the phantom lines as they are black an look stock .


https://www.pelicanparts.com/catalog...pg3.htm#item17

If makes a significant performance difference.

Look for DOT certified versions that have protective sheathing.

If you live somewhere they salt the roads in the winter , it's worth it .