Do you have ones that psylla have taken out of production due to pear decline as discussed in the video or do you think thst is strictly a regional problem with ohxf rootstocks? We know they grow 2/3 of the pears in that region it is only fair i suppose they have 2/3 of all the problems. The pear trees that are 200 years old still produce frequently. Keep in mind the 200 year old pear tree may be the 1 out of the 100 pear trees still alive.
As an example the endicott pear discussed in this post was over 400 years old. Imagine something here before the United States was formed
In 1630 John Endecott planted that pear tree!
Maine is working on projects to locate ancient pears in that state. "A dedicated team of fruit explorers have been looking around the state for the oldest pear trees still alive in effort to preserve valuable genetic diversity of Pyrus before its lost forever. Pears are one of the longest lived of all fruit trees and are known to exceed 350 years old. " Old Pears Gain Ground in the Maine Heritage Orchard - Maine Organic Farmers and Gardeners
High density pear orchards sound good to many people but the truth is the modern way of growing pears is expensive and not guaranteed to return any profit at all. Here is a realistic article about what a pear grower is facing. Growing pains for pear growers - Good Fruit Grower
Here is the other side of it endorsing dwarf pears but keep in mind most supplies have double or tripled in price since this article was written Pear orchards will have to be high density - Good Fruit Grower.