Same, really love them, as you can wear them for hours and they cause no pressure or uncomfort. ANC is great too. I use them for work.

Depends what device you run, but Xournal++ is useful. Otherwise pdftk.

It's my daily driver. It has incredible compatibility and very nice features, for example the rule based filter actions, header matching, which immensely boosts my workflow efficiency. Not to mention the calendars and tasks integration and the great extensibility via the plugin system.

Thunderbird is a great example of community driven awesomeness.

2010 MacBook Pro, still runs Arch with ease (back when I set it up I had more time than I do now, would go with a less DIY-ish distro nowadays, probably something Debian based)

The only chore was to get the RTC alarm wake up working, which was a bit hacky.