It can happen that if you're trying to do something with a lot of little localized bumps, lumps or folds in it that a polygon mesh based modeling program can just be a better fit for that type of project rather than MoI. They're a lot more focused just in general on making organic shapes which is not really the target of a CAD program.

Sometimes a hybrid approach can be good though too, like build larger sort of "idealized" forms in MoI, then bring that into 3D-Coat and add smaller level details with brush strokes there...

- Michael