I've discovered how laborious sanding/filing the bottom of the nut is, although I was doing it by hand, rather than DarkMark's belt sander trick!

I've started on the cheap plastic nut that came with the neck, to get a bit of practice in before trying on the bone nut upgrade I bought with the PB kit. Makes me think that nut files are the way to go...except for the £70-odd for a decent set. There seem to be some at around £5-6, then various prices up to about £20 before getting to Hosco sets at £70.

Has anyone tried these cheap sets? Are they so horrible as to be worthless?