Hi Steve, actually n-gons can give you a more efficient and cleaner structure in certain ways as well. Like in your example model there all the planar surfaces (top and bottom caps and 4 vertical side walls) will just have 1 single n-gon for those spots. Having all quads would require those spots to be tiled into a bunch of little small quad fragments instead of just 1 face.

Having a smaller number of elements like that can be nice in several ways - poly count can be lower, wireframe can be sparser, things like selecting faces for assigning properties can be easier, ... The main thing that doesn't fit is applying sub-d smoothing. But if your model is finished, there is no need to apply sub-d smoothing to it anyway.

On the other hand if you do want to do sub-d smoothing in the general case I recommend using a poly modeler to create the mesh for that since they have tools that are specifically focused on making topology for that particular purpose. In certain special cases you could use MoI for that, like if you use the dicing technique you showed earlier or if you have just a single untrimmed surface that can go into quads more easily but in general MoI's solid modeling toolset and n-gon mesh generation just is not the right tool for the job of producing sub-d quad meshes, it's focused on generating render-ready efficient n-gon meshes instead which is a totally different kind of mesh structure.

- Michael