John, the technical differences between Desktop and Pro are itemized at the Vectric site, but there’s an easier solution.
Get Vcarve Desktop and use that until you need something that is in the Pro version. All you will pay is the difference between the two at some time in the future. That’s the way they do it.
I have Desktop. It is much easier to edit with. I’m carving some 3D stuff now and can change enough of the 3D models to make nice stuff. The main limit of Desktop is that you are limited to a maximum carving of 25" (I think) square. Well, so far, I haven’t needed to do anything more than 24" square. I figured that if I start hitting that limit, I probably should buy a 4’ x 8’ machine.