I got two of these at Lexington's farmers market, one so different from the other that maybe two varieties got confused in the box.
I am describing the more traditional-looking of the two (shown): medium sized, yellow-green with a streaky red blush with some faint speckles that you have to look very carefully to see. I had thought my mystery apple might turn out to be one of these, but based on appearance alone I'd say not so even before tasting it.
The taste is also different--and quite fine--spicy and floral, nicely balanced though there is a hint of pine in the acid notes. Of course these might be a little early, which would make the flavor sharper.
If the Paula Red is the most "McIntosh-like" of the early apples, this one is the most Macoun-like. I like it best so far, I think; the flavors fairly burst forth at first though it does go a bit flat and woody at the end as the the juice thins out.
The flesh is fine-grained and white with a hint of green, crisp for being a little tender.
Wikipedia says Red Gravenstein is "considered a sport not a true variety," and Trees of Antiquity calls it "a red sport...similar to Gravenstein but sweeter."