N. Spy is a great cider apple. I've used it up to 90% of a blend with success along with a aromatic compliment. Has a very subtle taste. Alone, it makes for a very light, crisp cider with flirty undertones. But when paired with spicy/smoked foods this apple explodes into a burst of flavor and character as those hidden flavors come to the surface.
I suspect that the Spy was historically used as a sharp cider apple with secondary use as a cooker. It's dual use allowed it to survive the prohibition purges when Americans literally destroyed many other classic cider apple varieties.