maximillianos - 8:36 pm on Jul 19, 2010 (gmt 0)
The biggest drawback is the built-in keyboard. It is actually more difficult to use than the virtual keyboard on the much smaller iPhone.
I think this is because the iPhone you can type very fast with your fingers/thumbs... while the iPad's keyboard is too large to hold and type comfortably, and even when you set it down it is just an awkward sized keyboard.
For any serious business usage you definitely need to buy the separate keyboard that uses Bluetooth to connect to the iPad.