I find no real difference it's a billiard with more wood and less rubber, I find a Churchwarden even with a billiard bowl smokes way cooler which is to be expected since the smoke travels further to get to your mouth but generally speaking small Canadian pipes and their Billiard counterparts that are similar in bowl size, capacity and length pretty much smoke about the same, a longer shank/stem would be somewhat cooler but the vast majority of these Dunhill pipes I have are pretty equal in size.
banjo