I have had terrible results with most of the seedlings I've got from the Arbor Day Foundation. The exception to this was when I placed a bulk order for hybrid hazelnuts . I have never purchased any fruit trees from them so I can't specifically comment on the quality of their fruit trees.
I would like to suggest an Amish nursery that I have ordered from yearly (for an number of years) and have always had great results. They have no website....you need to call or write to request a catalog. Trees are low priced.
2784 Murdock Rd, Medina NY 14103
phone: (585) 798-6198 (best time to call is AM)
Toll-free voice mail for catalog requests only: 1-866-600-5203.
David Schlabach has written a book which I think is a jewel and is largely unknown. It's availble through his nursery and I also found it on line here:
Easy to undrstand and full of common sense.