Courtesy of Engadget
Kokatu had their hands-on experience with the 3DS Slidepad Expansion, which looks ugly and hideous. This is what they have to say:
QUOTE said:The "3DS Kakuchou Slide Pad" or "3DS Expansion Slide Pad" is powered by a AAA battery. It is surprisingly light in the hand. I thought it would be heavier, but it's not.
The add-on does feel reasonably solid. It's not a drag to hold. The backside, with numerous exposed holes for screws looks cheap.
From Engadget:
QUOTEThe new right-hand circle pad feels just as solid as the handheld's dedicated pad, and didn't significantly obstruct our access to the 3DS' face buttons. All in all, the cradle is a comfortable, if awkwardly large extension to the 3DS that doesn't seem to compromise the handheld's existing input.
The full article can be read here.
For Engadget's hands-on experience, it's here