Ok, so I just ate half of one after I got home. Pretty good, a little sweet for my taste, but a lot more complex than just sweetness. There almost seems to be some floral-ness to it, like the Envy apples have (they're even sweeter yet).
I don't think I'd cook with it; it seems like a good solid eating apple though, and pretty firm (I hate soft apples). I'd have to say that there are some apples I like better, but that just comes down to personal taste. I actually like the tarter apples a lot, but don't mind sweet apples as long as sweet isn't the only party trick. I'd probably keep trying the kinds I haven't had (or haven't had in a while) instead of buying more Cosmic Crisp. It's good, but it's not a showstopper, and there so many other good apples out there that I can't say it's the best apple.
Now, if I can just find some Cortlands and have a nice nostalgia trip to my youth.... And make a freezer full of pies, because Cortlands mixed with Macs make a ridiculous pie.