I like AC's myself. In a AC 50, which is what I normally use, even if too much flow, I just put in my AC 20 impeller, I just use the AC mechanical and bio media. Why I like the 50 is it fits a bag of Purigen almost perfectly which is nice.
I only use a prefilter if I need to. I used the Fluval ones forever and they got clogged easily. I would swap them out so I could thoroughly clean them. I found using a courser sponge worked better, I just made one out of an AC sponge. It didn't look as nice but worked better over time.
I just picked up a C2 for my 10 gallon and am happy with it so far. I run everything that comes with it minus the carbon and I jammed a pre-cycled pot scrubber in there instead. I like the the fact that I can take out the foam for quick cleaning without disturbing everything else.