This is the one I like the most. Fits easily on a desk. The backfill bit is in it. Really, application is the key to the right amount of product on the nail. Putting too much on means having to remove what was applied.
This is a very inexpensive piece of equipment. We use it for French Backfills only. I had one tech who used a very nice e-file for everything, even removing the polish on acrylic overlays. The rest of our techs were hand filing trained.
I have always been a hand filer. Learning to apply the product as close as possible to the desired finished nail will eventually eliminate the need for strong reshaping by an e-file.