I'm late to the post but want to share how much I like these new files. I have been using the Julip glass file for some time but this is so nice and the laser finish makes all the difference.
I use a magnifying desk light to do my nails and can see the nail dust comes off the nail in a different texture than the reg. glass file. This file is nice for cleanng off the dry cuticle attached to the nail above the live cuticle.
It is also good for buffing down a rough dry skin edge that has been clipped off at the sides of the nails. Additionally, it cleans the underside of the fingernail and makes them whiter. I can see the finished edges of my nails under the magnification and they are polished!
I tried the quick buff demo, I think they show three swipes across. My older nails are uneven and only parts of my nails shine. I am very cautious about buffing as I recall many years ago there were problems with over buffing and nail thinning. (I think the buffers were not sold for a while.) I'm not going to buff because I an just going to use my Duri Rejuvicote after filing.
The foot file works well also. My feet feel much smoother than when I have used other methods.
I don't think I will ever part with my new files.