It is very easy to argue the point that each camera's specific raw converter will give the best raw file. The camera makers are still a little secretive about certain things about their products. CS2 does do a great job and is usually faster than the camera specific software.
Before going out and spending big money on an upgrade or new software try this. Making sure your exposure is correct, shoot a grey card frame to set your custom white balance and set your camera to output a raw and large jpeg. I know on my MarkII the raw and jpeg look vastly different. The custom wb should give you perfect skin tones if exposed properly and give your raw file a good kelvin number to work with as well. If everything is done correctly, the large jpeg should be a very usable file, unless you have a specific reason for working in raw.
If you really need the flexibility of a huge raw file, pull it in thru DPP or your camera's software and output a jpeg thru it. Even if it is painfully slow, it should still produce the most correct raw file. Canon, Nikon, Fuji, etc. all put tag information in their raw files that their software knows how to handle. CS and CS2 do a great job of "guessing" what needs to be done. See if you like the results from this workflow.
I will say that CS2 does a much better job at raw conversion than CS and for most that was reason enough to upgrade.