I used to go to a sharpening service (and indeed, posts by me about it can be found in the archives), but ultimately found it unnecessary. Although doing it oneself, with a mousepad & sandpaper (or something similar) is tedious, it actually gets better results if done right.
The trick is sharpening the recurve, which has a concave grind. This, I'm finding, is best done separately, by sandpaper wrapped over a large eraser, or a similar set-up.
I realize that this isn't the answer you wanted, but it's what my own experience has borne out.