I have not done both, but have looking into both, so I may be able to answer your questions:
- The Canadian DAT is not computerized
- The Canadian DAT is offered only in November and February
- The Canadian and American DAT differ in the sciences section. The Canadian DAT does not include organic chemistry in the sciences section (only biology and inorganic chemistry are tested).
- The Canadian DAT does not have a quanitative reasoning/mathematics component
- The Canadian DAT includes a manual dexterity section in which you are given 30 minutes to carve a soap
- Canadian PAT and American PAT are exactly the same, except for the hole punching parts, I think on the Candian PAT only one hole is punched
- Canadian and American RC is the exact same (3 passages with 15-17 quetions per passage)
- The Canadian DAT is accepted by most American schools, and the American DAT is not accepted by any Canadian school
I would say, in my opinion, the American DAT seems a bit more difficult since doing a computerized exam takes strategic planning of its own, and you have to study organic chemistry and QR.