There are two tanks in my office running the Coralife Super Skimmer. Wow, they collect gunk like there is no tomorrow! Plus they cost less than $80 from big als online!
The only issue with them in a small tank is that the in-tank pump is fricken' massive, and the "anti-bubble" trap is equally massive. I don't have measurements but it's pretty intrusive in a 10g tank. In a 15 or 20g tank, it's less noticable. It's a great skimmer, from what I've seen! If you are clever with rock work, you won't notice it. Also, check the massive thread on the skimmer (search RC) and take note of the "overflow" problems that some people have had. Mostly back-pressure problems that some have resolved. And, of course, if you drill an "anti-overflow" hole in the collection cup and route it back into the tank, it's not a problem.
I have two AquaC EV-120's (big in sump skimmers) and they work great. I bought the Remora for $60 used, so I can't complain about it.
V