Here is a non-partial scientific article that describe the issue that you are encountering. The software that you are comparing to offers more than just a planar option but also describes methods for handling a constant cusp height.
BobCAD-CAM advertises that we offer a planar tool path. It is my opinion that there are other CAM software companies that provide both a better product and much better service for their product than BobCAD does. BobCAD refused to refund our money, saying it was not their responsibility to understand what their software would not do. This experience suggested to us that the ability of the add on module for 5-axis machining to generate useful code, where the physics and math is much more involved, would also be in question. Below you will find the timeline of our suffering as we attempted to get BobCAD to generate code to machine this relatively simple part successfully. BobCAD failed miserably at generating code which would create a useable part. The first part for which we attempted to generate code was a 3D contour part which we had been machining successfully for years with code generated from the software in use prior to our purchase of BobCAD.
My company purchased the 3-axis BobCAD-CAM module to replace the 3-axis CAM software we were previously using and to upgrade to a CAM product with an available 5-axis programming module.