Not so much fun to type long documents on. Like I said, if there was a good mechanical bluetooth keyboard that might do it...
Any bluetooth keyboard would work.....just find one you like.
I voted iPad mini because I use that more often than not. However I do use my MacBook Air quite freqently for graphic design and will be using both the MacBook Air and iPad mini heavily for my online MBA program. Textbooks on the iPad mini, coursework on the MacBook Air.
Really love both devices.