Personally, I LOVE the sideboards at Chambers Bay. I think it is one of those features that really helps higher handicappers while making it more challenging for major tournaments.
Right now, when the greens are running slow, the sideboards are great since it makes your target larger and you can favor one side over the other.
However, when the greens are running fast, the sideboards will repel anything close to the pin. On #9, I expect the toughest pin position to be the back left corner and front left for the US Am and US Open. If the green is running 10 or 11, if you miss the green to the left, I believe you will be lucky to have your ball stop on the green, most balls will pick up so much speed, it will roll right off the green (or be 80 feet away facing a tough uphill putt). It will make #9 much more interesting hole for the Open compared to everyday play.
I am a fan of any course feature that benefits high handicappers while making things more interesting for tournament players.