The Toronto GoodLife Marathon is a fast, net downhill course from Mel Lastman Square to Ontario Place. It one of the fastest courses in Canada and is a very good course for PRs and Boston Qualifiers.
The course drops about 105m (350 feet) from the start to finish. However, there are some rolling hills in the first 7+ miles of the race. After the long descent from just past mile 7, the second half of the course is almost completely flat.