I like my FX5 although I do have some small issues with it but I can find almost any issue with any filter. I do love my Aquatop filters because they are simple, have baskets and the quick disconnects are IMO one of the best on the market. I believe the marineland C series also use these disconnects. I also really like Eheims and probably would have bought the 2262 if it wasn't twice the price. I am still considering buying one anyways but $400 makes me consider setting up my larger tank and going with a sump.
I like the C-Series I'm running two now holds way more media than the FX5 in fact sometime I'm at a loss what to put in all the trays It is slightly louder but not enough to really notice. It weighs a ton tough with a bunch of bio media full.