I have an Eshopps single, in a 75 gallon tank and it works perfectly. I am new to this hobby myself (9 months) and started with a Marineland overflow box that was recommended to me from a local pet store in Round Rock, man what a piece of junk that was. I switched over to the Eshopps and I am able to run my return pump at max and the overflow box keeps up with the flow easily. It does make a bit of noise but I am ok with it.

Also to reply to a post within this post, I put a check valve in line with the return pump line and return siphon is no more. Drilling holes also works to break siphons.