Something I want to mention here, just because a graft survives doesn't mean it's graft compatible. Sometimes grafting incompatibilities can show up later, a year or two later. It is believed this may likely be due to differing grow rates between the two, and this type of delayed graft incompatibility is particularly common when the scion (top part) is the one that has a slower growth rate. Then the base variety has a tendency to overgrow the graft, and the grafted part isn't able to draw much energy out of the tree because most of the energy is being diverted to natural growth coming out of the rootstock variety.
Even if survival is long-term, it may still not be considered "graft compatible". The tree could be heavily dwarfed or stunted, and may not be the healthiest or grow the most vigorously. This could potentially affect fruit set.
Usually heavy dwarfing has an effect of inducing early precociousness (fruits, or more fruits begin growing early in the tree's juvenile lifespan), but if the dwarfing is severe enough that it is stunting growth, there could be the reverse effect.