The Greengage is rather an old fashioned fruit; I can't imagine that many would add them to a modern orchard these days.
Our tree, as usual, has been covered in fruit. Most have bugs inside, but the good ones are easily identifiable. At the moment they are dropping by the barrow-load, and have become so sweet that they are inedible.
I previously picked just a couple of Kilos (above); some we ate simply stewed with Lemon juice and a dash of Sugar, the rest were packed into bags and frozen.
The main problem with Greengages (if indeed it is a problem) is raking-up all that fallen fruit. They are easily squashed, and the task is particularly messy. Our tree is badly situated on the lawn; right in front of our sitting room. Yuk.