After trying both, I think the Cannisters are more efficient then hob
type, the water is sucked through all the media, rather then left to find it's own "easiest path"..
I have both, and the hob
is far more work and needs frequent washing of the cartridges to keep it from bypassing the media.. (there is no bypass in a cannister)
the Fluval line, which is the cannister I have, are lower cost then Ehiem and work very well, the 204 is a bit better then the 104 for the additional compartment, this allows you to use floss, carbon and bio-rings (carbon and biorings are included, but carbon should be replaced every month if you choose to use it) floss, whenever you feel like it or the flow slows down.