I would highly recommend spending a little bit more (ok, double) and investing in a TypeMatrix 2030.[0] The size/mouse position thing is important I think - and the 2030 is of comparable size - but it's nothing compared to having vertically aligned keys and the most used buttons (enter/backspace) in the middle. Also the build quality is superb. I could never go back.

    [0]: http://www.typematrix.com/