Well put, smilingcat! While not at all minor, I completely forgot about the safety issue involved in riding on aero bars, the primary one being access to brakes, as you mentioned.

I have done several group rides with people who have aero bars, and frankly, I try to stay away from them for the safety reasons as well as the fact that the steering is a little tricky and can make the bike/rider unpredictable.

SheFly