Let's start by noting that MusicNomad nut files are among the most expensive (at least among the ones available in Thomann).
Based on that, my expectations of the quality were very high.
Upon receiving the set (I didn't use it immediately because I didn't need to; I used some of the files after a month or something), I noticed that one of the files (the .017" one) was defective. The diamond coating was missing entirely from the blade's edge, and the file could not cut through anything.
I sent back the whole set (I had to since I bought it as a set) and waited some days for the .017" file to be replaced. The set came back with the .017" replaced, and it worked. But days later, I needed to use the .024" for the first time, and I noticed that it also suffered the same defect. At that point, I was too disappointed to re-send the whole set.
Now, the positives:
The files are excellent when not defective. The plastic grip helps you be precise when filing, but you can also use the files without the grip in tiny spaces where the whole grip might prevent you from filing.
The diamond coating / sanding surface extends on both sides of the file, which is great when you need to open deep cuts and want to create a wider-to-narrow slot. I also bought some extra nut files in different sizes.
Conclusion:
I suggest Musicnomad nut files only if you are okay with the possibility of receiving defective ones and having to return or replace them.