OK, here you go:
cockpits:
realair:

A2A:

the difference is larger in the sim, as the A2A panel vibrates with the engine, and the centre panel vibrates at a different frequency from the main panel..and everything is clickable of course You also have to pay attention to those guages, as things can go horribly wrong. Fun detail, in the Mk.1 you get a handpump for the landing gear...
A2A wins this round for me with a clear margin.
On to the exterior:
Real Air:

A2A:

from a distance, they are evenly matched, but when you get closer:
Realair:

A2A:

the A2A version has much higher resolution textures, all the little stencils are present and readable, the panellines are finer, the textures are sharper and crispier.
And that is just looking at the out/inside, A2A also has the accusim, which gives you wonderful sounds (groaning brakes for instance) and an engine that is very much alive. You have to take care of it, and then it still can give problems, it's British after all. It reminds me of my old Triumph and BSA motorcycles, usually everything was fine if you didn't overdo things, but sometimes...There's a wonderful unpredictablity in the A2A Spit. With realair, go full throttle for more than the allowed time and your engine will blow up, which was (and is) fun a few years ago, but