Checking out the window is not a bad idea, the sidestick could be wired up the wrong way around (happened to Lufthansa). However, from my seat i can see the aileron on the A319/A320, but not on the A321 anymore. No clue how it is on the bigger buses.
Apart from that, unlike the interconnected system in the Boeings each pilot has to do a separate control check on the airbus.