maybe i'm really missing the point, but once you attach a keyboard to an ipad you've are bound to have a sub-par user experience.

in terms of portability, i see no difference between ipad + kb and a macbook air. heck, i see very little difference between ipad + kb and ipad + macbook air, which is what i carry around. ipad for reading, macbook air for coding and writing.

iOS does not seem like an environment designed for people who spend most of their time writing and typing or otherwise creating. rather, it is an environment optimized for what most people do with their computers most of the time: consume information. that doesn't mean you can't create on the ipad. OSX, on the other hand, is such an environment. there is no reason to pick either or, you can have both at relatively low cost.