some people hate the prizm i will have to admit they are a pain to set up but i think by far they are the best on the market for the size tank they should be used for i love mine i also think the seaclone stincks mo
i have heard a lot of negatives about he prizm's especially on tanks over 60g. I run a CPR bakpak on my 55g and have never had a problem with it. works great.
I run two of them. Small and unobstrusive as hang ons go. Don't expect the efficiency of a sump type skimmer though. I'm ok with mine but if I had it do over I'd go the sump route exclusively. Goes to show though that in this hobby there any many ways to accomplish the same thing. Once properly tuned you'll like it ok.