Hmm...
OK, I'll try.
I didn't follow Johnny's skating that closely before this year's Nats, so I'm not sure if he can sustain this level of consistency for long. If he can - wow. IMO consistency is Andrei's weakest point. He also tends to get angry at himself when he makes a mistake, and after that the rest of his performance usually suffers.
I haven't seen Johnny live (at least I don't think I have, lol), so I can only comment on his skating from a tv perspective. And on tv his jumps at the Nats looked great. High, tight and effortless. Andrei's jumps can be spectacular. If he lands them, that is. Especially his huge 3a (some people say that because it's so huge he can't land it sometimes). I think he's a natural jumper. He also have 'cat's legs'; can save jumps not many people could.
Footwork: from what I've seen, I have to give Andrei the upper hand. He's definitely becoming one of the 'footwork guys.' I'd have to see Johnny do a more intricate footwork to form a more informed opinion about what he can do. I loved they way his whole body moved at Nats, but his footwork didn't have much complexity to it.
Spins: it's the area they both could work a little more on. I love Johnny's strange positions, and his line, but his spins could be faster. Andrei has a nice deep sit spin, and his camel position is exquisite, but generally his spins are much too slow (that is, they really slow down at the end). Btw, he used to do Biellmann (rather nice), but he got rid of it for this season. He does a few of Yags' spins instead. He plans to bring Biellmann back (but I hope he won't, since, like he said, it was hurting his back).
Andrei seems more passionate in his skating, while Johnny is more lyrical. They have different styles (and Andrei still hasn't really found his), I like them both very much. It's funny how both can flow on the ice, even if they do it differently (Andrei reminds me of Kulik quite a bit). As for their chances against each other right now -- most certainly Johnny would beat Andrei. The latter still has to learn how to skate as a senior, Johnny's shown at Nats that he can do it.
Btw, I don't know how successful Johnny has been in landing a quad in competition (I think he fell on it at last year's Nats?). I think I've read he lands it in practice with a 50% success rate. Tarasova's said (I think it was she) that Andrei does it in practice with a 75% success rate, but I doubt she'll put it in his programs in a near future. I think Johnny is planning to do one at Worlds, but I can be wrong.