I use iron cad inovate. Super easy to draw complex solid models and assemblies certain ways. The module I have does many things like bolts, gears.... These do help and down right automate many tasks. Also works real well with Sprutcam. As mentioned above models with preset ucs and fixtures imported into position with little effort. Still Expensive software even for the one module I own. If I do change cad programs it will be to a subscription of inventor . About same cost as what I use with update cost.