I seriously thought about buying one of those, but after trying one I found it to be much more awkward than a loupe. The real convenience of the loupe is having it at the honing bench right next to the tape and scissors, very easy to give a quick wipe and check the edge without putting the razor down - and no fiddling with a focusing mechanism. The 30x lens is more than adequate for at least 95% of my needs, and the 60x is there if I really feel the need to see something in more detail. That being said, if I find a problem, I don't bother examining it in too much detail, I just hone it out and keep moving. I also have a USB microscope, but use it almost exclusively for forum photos.