I didn't re-chamber a NEF, but I did re-barrel my Stevens 200 to a 17 Fireball. So far I shot about 250 rounds down the tube and I will say that I am very impressed with this "specialty caliber." I did this Fireball project specifically for fox hunting (which is why I call it a specialty caliber....fur friendly caliber).
IMHO, I would tell you to have it done. I do all my own reloading and even with the tiny 25gr bullets, these are not difficult to load. I've whacked lots of paper and a few groundhogs with 'em and with virtually no recoil, you can just watch through the scope as your target goes plop.
I had a 17hmr one time and sold it. I won't be selling this Fireball anytime soon. It's a keeper.
Dave