Review (4/5): Surprisingly good for the price
For the price, I'm genuinely surprised with this nail drill. First of all, it doesn't suffer from the two major issues most cheap nail drills face: lack of torque and internal wobbling. A lack of torque is when the rotation mechanism stalls out if you press hard enough against the nail. You'll know a nail drill has internal wobbling because it will almost tickle or feel uncomfortable when you file your nails.
With that being said, here's what I don't like: I prefer much thinner nail drills. Even if you "choke up" your grip onto the thinner part of the drill it's still thick enough to make my hands tired if I'm using it for longer than a few minutes. I can't imagine this being comfortable to use all day in a nail salon. Next, the instructions. It took me way too long to figure out how to change the drill bit, partly due to the vague instructions and partly because I had to use so much force I genuinely thought I was going to break it. The twist mechanism is misleading. You turn it and it stops so you think you're done turning it but in actuality you have to keep turning it until you hear a click.
It also would be nice for the manufacturer to explain the differences between all the drill bits and what the intended use case is for each one.
FOR THOSE OF YOU THAT CAN'T CHANGE THE DRILL BIT:
Turn the top portion of the drill toward the side labeled "R" until you hear a click (this is important) use pliers and pull out the drill bit. You'll need to use more force than you think.
Once you've removed the drill bit, stop turning the top portion of the drill toward "R". The mechanism will go back to the center by itself. Pick your desired drill bit and put it where the old drill bit was. Turn the top portion of the drill towards the labeled "S" until you hear a click to secure the drill bit (The drill bit WILL fall out if you don't twist it towards "S" until you hear a click).