I have 3 of them. I bought them at different times. I really like them and they will run for years as good as a new one. I don't think they clog any more than another canister filter. I've even used them for young goldfish (and goldfish are messy!).
I use them with out any carbon.
The set up is kinda backwards (as the bio media is infront of the sponge) however it does not seem to make a difference really.
Hope this helps. What will you use the filter for?