I would imagine Desktop Mode with touch is more accurate in 8 than in 7.
Meh, not noticeably.
It might be the case that on a a new Windows 8 ready screen with ten point capacitive touch, the desktop works better in 8 than in 7 (somehow?). But on a 10.1 inch 1366 x 768 resolution touch screen machine that had run 7, which has been loaded with eight, the desktop is still the desktop -- full of fiddly little buttons that are very difficult to select accurately on a touch screen.
*long tap an application file to bring up the context menu, hunt and peck to find the application properties, hunt and peck to select the compatibility tab, hunt and peck to open the compatibility drop down menu, select compatibility for win 7... stupid fiddly bit! Let me try that again...*
You'll never know how much you appreciated your arrow keys until you haven't got them anymore, a problem that most Surface users won't encounter because they'll have the mag keyboard. It's a brilliant product pairing.