I have an EV-180 on my 150. I'd rate it at about 7.5. I don't have a hair of algae, but can't seem get rid of my Valonia (grape looking algae) and I maintain 0 nitrates/phosphates. So, non-scientifically, it works to remove the bad things, and it fits in a smaller sump space, but it could be better, because I think my 100 micron filter sock takes out most of the crap. Also, don't go with their recommendation for pump size, and buy the Mag 9.5, and dial it down somewhat as needed. I went with their recommendation for the Iwaki, and it didn't produce anything after weeks of tweeking...save your $$
After reading other users recommendations, and seeing the Bubble Masters and Octopus', Euro's, etc. and reading about bubble size and air draw. I now see what a great skimmer can do.
It still comes down to price & space availability.
For what it's worth, the dual recirc Octopus 150 runs about the same $$ as the EV-180. A Bubble Master 200 is about $100 more, but there are several mods on this forum like the mesh wheel conversion for the needle wheel skimmers like the Octopus and BM that will greatly improve upon that already great design.