Louis thanks for the kind offer, but although ive never used them for shaving, i have used them with my work and actually have a few left here.
I hand build custom fishing rods and use DE's for cutting both cotton and polyester whipping thread.
Ive read numerous times that they are one of the very sharpest blades on the market, so bought 25 a couple of years ago to try for work. Absolutely no better than any other DE or SE blade ive used when it comes to cutting thin thread - and actually noticeably worse than some others. I'm using Astra SP with my work atm, which are definately sharper and much longer lasting than a Feather.
Weird eh? You'd have thought that if they were high performance with facial hair then they would also be the same with 0.17mm cotton or polyester thread.
(It was only the the seemingly good price that made me think of buying some to try for shaving!)