As with most software it's a matter of learning the limitations and then finding a work-around to solve the problem. As for the Vertex Modeler I avoid it. Only reason being is that I started with RDS3 and it only had the Spline Modeler and I'm more familiar with that (and it saves to smaller files, is faster, more flexible). The lath operation has problems there also, the closer the "shape" to the axis point the more problematic it is. If you put-up an image of what you need someone may be able to give you a good answer. Also, litst has some tuts up at his site for the mesh modeler.