I've been interested in purchasing a Macbook air for some time. The hard edge of my Macbook Pro is really uncomfortable and it looks like the Air may have this same comfort flaw. Does it?
Wear a mask.
Also, the amount of grinding necessary to get a smooth edge is not much at all. This is a quick job, and leaves the same grey color.
Finally, there are covers that remove the hard edge.
I basically just gauged it by eye. Light, slow, take your time.
I use a Pro at work, and have used friends' Airs at times. Since the Air is much thinner, I don't recall the hard edge being a problem.
As always, best to just walk into a store and try it out!