I've got the 65-gal version. I'm very happy with it. Blows away my Prizm. It's quiet too. The only thing I don't like is that it's very obtrusive if you use it HOT. The bubble trap is pretty big & ugly. I don't use it anymore since the unit doesn't spit out any microbubbles anymore.
I have the 220 on my 180 and for a cheap skimmer it works really well. I'm also not fond of the bubble trap but I saw a mod somwhere where the guy just slapped a "T" on the outlet and droped a piece of PVS to the waterline in the sump. I've not had a chance to hit the store so i haven't done it yet. Pulls out some nice scum. I'd give it an 10 out of 10 for the price.
i have a css65 and i really like it. i have mine in the sump so it is out of the way. it really produces dark, smelly skimmate nicely. i give it a 9 or 10. for the price you cant beat it. mine seemed noisey at first, but now that it has been running for a few months, it really quieted down alot. i paid less for my css65 than my buddy did for his replacement pump for is asm. not knocking the asm as it is a very nice skimmer, just dont like the price.