I can't compare this Evassap Electric Nail "drill" to the others. I chose it after a lot of research. I am new to this kind of device. Did I choose the best one? Who knows! But what I can tell you is that this is an efficient little machine and it lights up with each use. It is battery operated. It works in a forward OR reverse direction, and has 10 speeds. It feels solid in my hand and is easy to work with. It charges efficiently, and that's where the electric cord comes in. It will charge by plugging in to your charging device without an electric wall plug in, but you CAN charge it that way too, as long as you have a wall outlet plug that accepts the unit's USB plug, which is how I charge it. It will last quite a while between charges; if it stops while you're using it, it's time to charge it. Absolutely DO read the manual it comes with before you use it! That's totally necessary! The manual is adequate but it's way too small and could explain things better; you'll figure it out but it takes a little doing. All the little parts it comes with work fine for polishing, buffing, etc. Don't force the needle-like thingy into the unit---it will stop when there's a little space between the unit and the "drill" bit. So far, I use it only as a grinder (with a little plastic shield included) which is DEFINITELY a necessary tool to much more speedily rid yourself of nail fungus---along with an antifungal diet, soaks, and UV-C light. I've had the Evassap now for about three months now and it works just fine.