If you are unhappy with the p/u, what's the worst that can happen?
Here are the two outcomes...
1) Your friend re-winds the pick up and you HATE it, but you didn't like it to begin with. Fortunately, you friend did this for free or at least cheap. No big loss. Now go buy a Seymore Duncan or any other quality pick up of your choosing.
2) Your friend re-winds the pick up and you LOVE it! Not only that, but your friend did it for free or at least cheap! Bonus!
The way I see it, you can't lose with letting your friend re-wind your pick up (as long as he has a bobbin spindle and a little experience doing this).