Product review (4 stars): Good for the price, blade reversible with some elbow grease.
I used these for a DIY project and not as a drop in replacement. The fans move a lot of air, and there is a bit of noise associated with them. That's to be expected. The "Low" is more like HIGH and the "High" is VERY HIGH. The off is still off. Or I guess VERY OFF. That shouldn't be a surprise ;)

The fan blade assembly on both of the fans I bought was slightly misaligned. That is, while the hole was centered, the fan was at an angle and wobbled up/down as it rotated. The fan blades are pressed on (and reversible), so I removed them, re seated them and was able to mostly straighten them up.

As shipped, the fan rotates so it pushes the air past the motor. To remove the plastic fan, I placed the "claw" part of a crowbar under the plastic fan to support it (so I didn't break any blades), then took a hammer and punch and tapped the center shaft to back it out. The fan is pressed on very, very tightly, but it will budge off. Be careful to properly support the plastic when you go to tap the center shaft and motor (assembly, one piece) off of the fan. It is a tight enough fit that you will break the plastic fan blades if you're not thinking things through properly-- but as long as you plan it out, it's pretty easy and takes 30 seconds.