At first I was very sceptic about the smaller size of this thing. I find the K20 very comfortable in my hands. This new battery grip however gives me the impression that it might provide the best of both worlds: even smaller then the K20 without the grip, and still very comfortable with grip attached. As my friend pointed out earlier today: the grip looks thicker and better to hold in portrait mode then the D-BG2.
For those that claim it's too big - you've obviously never seen the (chinese?) third party grip for the K100, now _that_ is huge, almost as big as the camera itself!