I have this on my 300gal system and it is truly a beast. Purchased it directly from Doug. The only downside to it of course is when you want to clean it you have to take the whole thing out of your sump to take it apart and clean, but i only do that 2 or 3 times a year so its not really that big of a deal for me. when i purchased it, i needed an in-sump skimmer which would be just as powerful as a regular skimmer.
Happens to be i now recently changed my sump and now need to swap it out for an external skimmer. I will tell you that I will indeed miss this skimmer once i find an external one to replace it.
it is hard to find reviews on it as in-sump skimmers of that size are not very common, but hey when you need it, you need it. Although it is pricey (hey, its a Deltec) I never regretted it, as a matter of fact, it ended up pulling me into Deltec's other products.
Go for it, you wont be sorry.
