I also mainly use Fusion360 at home (Inventor at work) now, before I used PTC Software (Wildfire and the free Creo).
You really don't have to bother much, since the low, mid and high settings are pretty much all you need. For simple mechanical parts low will do. I did not have any part so far where the high setting was not good enough. Being lazy I only use high, because S3D is really good at handling big stl files (had some lithophanes with > 150 MB, no problem).
Also, compared to other CAD software, the mesh generation of Fusion360 is quite good. And what really made me happy recently is the new mesh module in the software itself. You can import and edit stl files there now. It even has good remesh capabilities.