Comments about Pentax BG3 Battery Grip for Pentax K200D:
This grip is great for doubling your battery capacity, and for overall surface area for a comfortable hand grip for standard (horizontal) and vertical shooting.
There is a foam rubber seal where the contacts mate with the camera body and seem to seal quite well. I wish there was some built in memory card storage, but this is not really a draw back.
I do have to really crank down the mounting screw to reduce perceived movement independent of the camera body.
Other than that the BG3 Battery Grip does what it is supposed to do for a modest price!