Well, I got one, and so far I like it. I got the 17" length to go in a 40 gal (36"x18") tank. I mounted it on the front, aiming back. I considered mounting on the side, but it didn't quite fit.
It was easy to mount - just slide the holder onto the lip of the tank. It is a tight enough fit that it won't knock off easily, but if it does, it is submersible. However, I am going to have to take some sand-paper to the corners of the holder, since I keep scratching myself on the corners when I reach in the tank
You can turn the LED tube to change where the light is aimed. which is very convenient. If I aim it into the tank, it seems pretty bright But if I aim it parallel to the water, it diffuses the light a lot. Then it seems reasonably lit in the back of the tank but too dim in the front of the tank, however. But I am pretty sure I will be able to figure out a way to aim or diffuse it (like the idea above) it to get lighting that pleases both me and the axies.
I am pretty sure I would not like this light mounted on the back of the tank, since the glare would be in my eyes when watching the tank, and there isn't something to shade the light in one direction.
It would be nice if you could reverse the side that the cord comes out of. Clearly, you can pop the light tube out, but the holder is not symmetric. However, the cord routing clips do keep it out of sight. Also, the switch has a suction cup to stick it to the outside of the tank in a location of your choice. The cord is nicely long.
This light produces enough high-frequency spectrum that GFP axies' eyes glow green, but it doesn't seem to bother them so far.
