I have the Air 1 and noticed the vibrations on the Air 2 at Best Buy. A lot of people on macrumous have complained about it along with the screen distortion issue.
http://forums.macrumors.com/showthread.php?t=1807295
I know it would drive me nuts since I play games on mine so I'm sticking with my Air 1. I suppose it really depends on how you use the device and what for. etc.