I tried using just the iPad and the on-screen keyboard took up too much of the screen for my liking. Bought an Apple Bluetooth keyboard - it was better, but function keys, etc are not fully supported. Eventually went back to using a MacBook Pro. For me having a keyboard; not having to prop up the iPad; and being able to function without a wireless broadband connection dropping out, slowing down is a more productive experience. And ... I really prefer to have bigger screen. Sometimes use the iPad in a Logitech dock as a second screen with AirDisplay - now that is convenient - but not on the road.

In your situation I would seriously consider getting a MacBook Air.