I used Generic 3D, Rhino3D for 6 years designing machinery, Solid Edge for 7 years designing machinery, and now use SolidWorks. For models used on a 3D printer you'd be hard pressed to find a better tool than Rhino. You get 25 uses for free before you decide whether to buy it. Remember though that the P in PC stands for personal. Software is very personal, it may have great capabilities and you may hate it. I use AutoCAD nearly every day, and hate it every day, but it's personal.