Well, it really depends on the kind of usage you give them. As a CEO I am always on the move, and there are a lot of surfaces and situations in which a laptop really isn't practical. Try the inconvenience of having to show a presentation on a lunch table with a laptop and you will understand why. Nothing beats the ease of passing an unobstrusive device over the table for the other person to check out what you are trying to show.
This may sound frivolous, but when you are trying to sell an idea, every bit of positive feeling on the other side really counts.
One of the best purchases I ever made.