I think this is a great choice for this product from MS. I look forward to having smaller options from the other OEMs for portability. My experience has been that 7" or 8" is perfect for extended use and portability. Larger than that gets unwieldy even with a kickstand.
For Surface 8 10" is good. For Surface RT I'd like about 8".
Personally, I think it can use a bigger screen. I am a digital artist, and this tablet would be perfect for drawing on the go if it had a larger screen. I think a 12.5 inch screen would make this the go to device for digital art.