Consider what a canister is.
It's a "tiny" (in comparison to most) pressurized sump.
Does by being pressurized do anything magical? not really.
Cans do tend to be somewhat quieter. Although sumps can be put in another room, or even on a separate floor to minimize water movement noise, if available.
The advantage of a sump (other than being generally a little less expensive), is maintenance can be much more simple (no need to dismantle anything) in fact when I do maintenance on mine, I don't turn anything off (unless servicing the pump). I just pull out mechanical, or bio media, rinse it out, and toss it back.
You also have the option of using quite a bit more media, both mechanical and bio, and you can easily add other filtration options in the sump, such as protein skimmers, bio towers, or fluidized beds.
As long as you don't begin by using one of the small, expensive commercial ones, or muck up a small sump tank, with baffles that restrict movement, and are basically only there for aesthetics.
My sumps are generally old, scratched up 50 or 75 gallon tanks, and I put heaters in them, so they aren't messing up the view in the main tank (and if you have big fish, that may destroy heaters of other equipment its great to have that equipment else where.
