That's exactly what I'm saying. When you test it for 30secs in the store you certainly feel it, but I own the Air 2 and I can tell you that after using it for a normal amount of time, say 20-30mins, you walk away from the session with your hands tingling. That's something a quick test just doesn't tell you.
And of course there's a lot of people using the speakers. I don't even own earphones (the ones that came with it stay in the box).
Okay, I gotta admit. If I use it with speakers for a long period of time it might get uncomfortable with tingling sensation in my hand. But then again I use earphones where I commonly use my iPad.
Maybe you could put some dampening materials then cover it with a case to weaken the vibration? All the while waiting for the issue to reach Apple's ears.