In the last few years, ornamental pears have become very popular in this area (southern Ontario) and most of those in my neighbour's yards are doing very well in our heavy clay soil, looking shapely and especially attractive in the spring. However, does anyone have longer term experience with varieties OTHER than Bradford, such as Chanticleer and Capital? Do these have the same longer term drawbacks that Deb describes so well for her Bradfords? I have to replace a diseased columnar Norway maple that was a legacy from the former owner of my home, and an ornamental pear was one option I was considering, Now I am not so sure.
Malcolm, Your native Canadian trees are the best choices. You might check your local horticulture extension, and find someone who knows all about the native trees. Also look around and even photograph older trees that you like and identify them. Sure you have some beautiful flowering trees to choose from, and you'll be glad for taking the extra time to decide.
Try a Serviceberry Tree, which will grow to about 25-35 ft tall, and are native to our woods around here - Western New York. Serviceberries have nice white flowers in the Spring. Also the fruit is quite delicious.