You'll receive a lot of varying opinions on filtration.....
I'm not familiar with the EX70, for hang on the backs I use Aquaclears exclusively and have been very happy with the performance, reliability and ease of maintenance.
On my larger tanks (75 gallon and 120 gallon) I use API Filstar filters and have been super happy with those as well.
Canisters generally have larger media baskets so they can hold larger quantities of media over the hang on the backs which equates to larger surface areas for larger, stronger bacteria colonies. I have also found them to be easier to customize with specialty media - they just have more options as they have more space...
Another plus for canisters to me is the ability to add spray bars to better direct the flow of water throughout the tank. Some of the Filstars have an adjustable flow spray bar so you can actually lessen or increase the flow of the water depending on the species of fish and plants.
My hang on the backs are quiet but not as quiet as the canisters - my canisters are super quiet.
Some keepers ease up on their maintenance schedules with canisters allowing them to run for months without being cleaned, not me - I usually clean hang on the backs and canisters every 30 days.
Either option will work fine, so would sponge filtration for that matter - to me it just comes down to economics, in most cases you will pay a little more for a canister.