I've got a Kodak 3900 with docking station, and as far as I understand it, it will charge any rechargeable batteries (providing they're in the camera of course!)It also provides 'one-touch' picture transfer. I must admit that overall, I like it. The only problem comes if your batteries run out and your not at home. I always carry some 'ordinary' batteries for emergiencies.
My son bought a Kodak 4300 with out the docking station. He uses a plug in battery charger that charges 4 metal halide cells at a time and He used to down load the pictures via a usb lead, but this needed the camera to be turned on while down loading. At the time he did not have £60 for for the docking station but soon after, we bought an epson 915 printer which allows the card to be plugged into it, and the images downloaded via the printer. So the docking station was not really needed. The plug in charger can charge different sizes of battery as well as metal halide and nickle cadmium. So if you use other rechargable batteries it might be worth considering the seperate charger?