I reground my S&M Heritage Jack because it was WAY too thick behind the edge. I also reground my dad's USA Schrade SP3 Firebird because he's had it so long that it has been sharpened up the bevel and it was getting a bit thick behind the edge. I did a scotchbrite belt finish on it and took it up to 1000 grit on the stones. He was impressed.
Not all traditional knives need a regrind, but when they do, it makes a world of difference!