A good solid piece of kit. Sturdy and feels more like a home console controller. The device does take batteries but will last you 100 or so hours, so no issues here.
This item is a must if you want to play Resident Evil Revelations or Metal Gear Solid 3D. Unfortunately there are very few games that support the Circle pad Pro at the moment, but these two games alone warrant buying it.
You can also play the games for hours without crippling your hand holidng the 3DS in it's basic form.
Pro's = Good build, make certain games instantly better, easy to attach and hold.
Negatives = Second Circle pad and extra trigger button should have been inbuilt to 3DS, lack or games supporting the Circle pad Pro.