The Tech Report published a review on the For Valve, is the Steam controller both a blessing and a curse A quote from the article:

Valve's Steam controller looks great on paper. It promises not just greater accuracy than conventional console gamepads, but also support for point-and-click titles that traditionally required a mouse and keyboard. There's a downside, though. As TR's Cyril Kowaliski learned first-hand, the Steam controller has a pretty steep learning curve—steep enough, perhaps, to put off some potential converts.

 For Valve, is the Steam controller both a blessing and a curse @ The Tech Report