Hello, I myself am using an Eshopps 800 and I have no complaints. Albeit, it is the first overflow I have ever owned. I was hesitant to go with it because I read many reviews, or seen videos, where people have lost the syphon over time. I now believe this was the case because the pump being used was not able to keep up with the overflows efficiency which would lead to slow water flow through the j-tube and eventually build up a big enough airpocket to break the syphon. That being said, make an honest attempt to account for your water pump's flow rate and buy an overflow box rated just above that amount. In other words I don't suggest buying an overflow rated for 800 gph
if your pump can only push 200 an hour. All that being said, I do not know of an overflow - that I saw while I was shopping for one - that did not maintain it's syphon after a power outage.