Check out Wings3D.
My modeling workflow is;
Create model in Autodesk Inventor
Import model into 3DS Max
Import model from 3DS Max into Wings3D.
Paint my model, then export from Wings3D to .X file.
There are two small bugs which impact this workflow, but they're easily worked around. One is that if Material & Appearance names contain a "/", then the model will not show in your DBPro app. So name all materials in Wings3D to simple letter names. And secondly, when exporting to .X the model flips on the X(?) axis, so you need to take this into account too.
