QGIS is truly excellent. I'm a frequent ESRI ArcGIS user, but I'm pushing to put QGIS more in our workflow, including field work. And I use it for personal GIS projects as well.
As ESRI moves farther away from making useful products that can adapt to fit our workflows, and more into rent seeking, I move more parts of our process to QGIS, and port more of our custom python tools over.
Most of our stuff is focused on calculation and interpolation on raster data, so a lot of numpy with appropriate hooks. Porting varies, sometimes it’s as simple as changing a couple of function calls to gdal, sometimes it’s trickier. I’ve only made it through a couple of the simpler tools, like a mesoscale wind map based energy production calculation and a wind resource grid interpolator that were originally standalone anyways. The gdal calls to read and write rasters are pretty easy to use.
As ESRI moves farther away from making useful products that can adapt to fit our workflows, and more into rent seeking, I move more parts of our process to QGIS, and port more of our custom python tools over.