I feel these are exceptional pumps at great prices. I've modded them and used them on a wave timer and they do an excellent job. They are made to turn on and off. I have never had a problem with them not turning back on.
Cons: The suction cups will eventually fail and you'll have a constant battle figuring out how to keep your maxijet up. However, there are products out there that let you hang your maxi-jet with a magnet.
I had a roaming anemone get chopped up in one of my maxi-jets. But that would have happened with any internal pump.
5/5 is what I give this line of product