I like these motors. They are extremely inexpensive and run well. I was impressed with the amount of punch they have on a 450 quad with 10 X 4.5 props and a 4S battery. I was expecting that quad to be slow just because of the size and prop size, but it really takes off with these motors. That's another thing - these motors are rated to work with 4S, which seems to be rare in this industry.
I've owned ten of these on two different quads. The only negative I have is that the threads seem to wear down fast and will strip eventually. Now I will admit I change props a lot just to try different combinations. It was probably at about 20 prop changes that two of these motors stripped while tightening. Unfortunately I don't see a way to replace the threads and the entire motors have to be replaced. Still, at this price they are worth it.