yeah that is my main gripe about the intuous 2 I have. 4x5 is really tiny. You can only use your wrist and not your arm as you draw. I like the 6x8 wacom pen and touch but those are almost $400 bucks here in the US.
the only problem then becomes clearing the space on the side of your keyboard for it and a mouse.
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675