We chose to use inkscape for part of an image generation toolkit because of the great command line options and the easy to modify source files.
As for the UI, ever since .91 they have fixed my biggest concern, and I'm really happy for the team. Rarely feel the pain and need to reach for illustrator on a windows machine!
At this point, I have not used Inkscape as someone else has been using it (not a power user). However, hearing about its command line options makes me want to investigate that immediately. I have been suggesting a CLI approach would be much better for us with all of the automation we are looking to implement. Thanks!
Some of my projects have only the icon svgs checked into the source repo and the build tool renders them to PNGs through inkscape. Works really well.