I don't know that either type of filter produces more biofiltration. It depends on the size of filter, how it's packed, etc.
Both can provide adequate biofiltration for most aquariums. The decision between HOT or canister filters usually hinges on other aspects: cost to purchase, cost of media, esthetics (what it looks like on you tank), longevity of the filter itself, and others.
Are you trying to decide which type of filter to get? If yes, you could write a bit about your situation and needs and I'm sure we could give you some more specific advice.
Jim