What open source generally does well:
- Stability - generally doesn't crash. Notepad++ is a rock but many "beta"-stage open tools are remarkably solid.
- Compatibility - usually opens, saves, and connects with a wide variety of different formats and services. Both LibreOffice and SMPlayer open/play 100+ more formats than their commercial rivals.
- Speed - compared to other tools, it might not be the fastest, but it's almost never the slowest.
- Configurable - there are almost always some additional options/tweaks, sometimes hundreds of them. The Firefox about:config tool is crammed with available tweaks.
- Roll-back options - if a new version introduces something ugly, it almost always lists older versions. For example, I temporarily went back to an earlier version of LibreOffice recently some months back.
- Behaves as expected - commercial software will frequently take out features with the next release because it's annoying to test or too few users care, but open source tools very rarely remove functionality. The steps or sequence you used last year to fix/modify an image in GIMP will be the same next year.
What it doesn't do well:
- Usability - there's almost always a learning curve. GIMP took a long time to learn.
- Documentation/Intro - usually poor, often non-existent. I won't name anyone specific, but many open source games generally have to be understood by mere trial and error alone.
- Interface - because features gradually increase over time and not at a steady or expected pace, a well-organized interface is the exception and not the rule. I could name a few apps that need a revamp.
- Minor bugs generally sit still - if there's an issue that has a workaround, it often doesn't get fixed. Firefox has an minor, intermittent address bar issue that's been around for years. But you can hit reload so ... *shrug*
Finally, I seem to have better experience with GPL-licensed software over time versus other licenses. I can't speak to differences in v2 vs. v3.