I do recognize that this is an old thread, BUT, it looks like more than a few of the posts here spoke of growing a number of varieties from seeds for fruit as well as some that grew specific rootstock to graft and grow different varieties.
Considering the significant rise in prices for grafted trees, I would be very interested in the status of these "experiments". Not only for actual time to produce fruit and the quality of it but also those who grew specific seedlings and grafted known scions. The latter of which I would also be interested in the successful grafts, how long it took to produce fruit.
Even with purchasing up to a larger grafted tree, I am hearing that it could take a couple more years in the ground to produce fruit. And to me, even if the seedling doesn't turn out to be a clone of a known variety, if it tastes good it is a win, if it isn't good, a known scion could still be grafted to it.