I've tried lots of wild apples, apples from trees with consumable apples grafted on to them etc. Some of them make crab apples taste sweet. Most apples are probably about as sour as lemons and fairly tiny, from grape to small plumb size. They make your belly hurt and generally aren't that pleasant to eat.

They're great for making pie or jam or such things. Homemade Apple crumble(crisp, I dunno whatever same shit...both good) is probably one of the best things next to homemade strawberry rhubarb pie, but either way, they're a far cry even from Granny Smith apples which, I enjoy, but as far as I know, most people use for baking.