The cascade is a canister filter, although the 700 is only rated 185 gph.
It all depends on what fish (and how many) you have. Heavily loaded tank (or messy fish) needs more filtration. It is not unusual to have 10x turnover per hour in a big cichlid or a goldies tank .... <2-3 x like you have is bare minimum .... and most filter makers are over optimistic with their numbers ... you are not likely to get the rated gph>
I like to over filter my tanks (almost a necessity in a goldies tank
). I have close to 10x turnover (750 gph tested). You prob don't need to go that overboard .... Personally, I think canisters are better for bigger tanks (Fluval, Filstars, Ehiems are top brands),although some do swear by a big HOB like the big AC's.