I think the biggest key or drawback to me is some skimmer pumps aren't designed to handle depths of water......That is my only reservation with running the XP5000 internally.....Skimmer depth of 6-6 1/2" doesn't leave me much headroom inside the stand.....Where as something along the lines of BM and Skimz so far the pumps are able to run at deeper depths....The problem lies in that no matter how I positioned the sump and tried to align it under the stand, with the size of the Octopus skimmer (which is totally massive) it would fall under a cross support in the stand.......Again no issue running the skimmer externally, but actually fired the pump I was going to use to feed the external skimmer, and to be totally honest the noise level sucks.....
I've used PanWorld in the past and had bad experience with their pumps being inconsistent and failing on my previous MRC beckett skimmer, but thought I'd give them another shot, but noise is bothersome, when I've worked pretty hard at keeping noise level down only to have a noisy pump such as that......