You will have stuff up in no time with DarkSDK. You dont have to worry about window creation, message pumps, device contexts, vertex formats, vertex buffers index buffers etc...
You can however IIRC get down to those functions with the DarkSDK if you really want to.
Trust me, get the DarkSDK, you will seriously get demos up and running, and games, in a fraction of the time, rather than if you were battling it out with C++ and DX.
With the DarkSDK, the model loading is done for you, the image loading, alpha blending, value interpolation, camera code, lighting etc etc...
get the idea ?