I have browsed through this thread over the time of its existence, but for some reason never responded to it (at least I don't think so, but I'm too lazy to go through all six pages to make sure).
I downshifted once in 2016, when I left my tenured full professor/department chair position at a four-year comprehensive university because it sucked. I won't get into all the ways it sucked, but suffice it to say I have not had one millisecond of regret since I drove away from that campus and never went back.
The "downshift" was that I went from that to full-time fiction writing. It was still a "full-time" job in my mind because I didn't have other employment, but I have not worked more than 35 hours a week since then, and these days work about 25-30. My plan is to do this for about five more years, but taper off even more, gradually.
To answer the questions in the OP:
- why you did it? See above paragraph about the suckage of academia
- what your downshift looks like? See above paragraph, lol
- what do you like about it? Um, everything? My favorite thing is that Sunday nights no longer send me into a funk, and I never have to get up in the morning and slog through a shower, getting ready, and a half-hour commute. Oh, and no more grading. Grading is the worst. And also, being my own boss, and having my time be my own. And getting to go on a relaxed morning walk every single day. Oh, and that we can take vacations any time of the year, instead of just summer or the the period between Christmas and about January 15. Really, there is so little that I don't prefer about this life.
- what isn't so awesome about it? Well, the self-employment thing does come with its own downside. I left academia because I was starting to feel like a slave to the job. And the concept of autonomy is a large part of the reason a lot of people are attracted to academia in the first place. I now have autonomy for sure, but it has been an adjustment to not push myself too hard and become a slave to my own self. I've gotten a lot better at that over the years.
- what are your plans going forward around downshifting and FIRE?
So, I quit my academic job at 49. That felt a lot like FIRE to me because my husband still had a job and I knew that if I never made another penny, we'd still be okay. Turned out, I was able to make more writing than I ever did at teaching, so in the end, I was able to retire my DH three years ago. Now he's retired, and I have a job where I can work part-time and make a full-time income. Since this job isn't particularly stressful, I'm content to do it basically like this for five more years, at which point I'll be 60. Then, my idea is I'll stop writing and then just manage my IP/marketing on about 10 hours a week. Or not. Who knows? The nice part is, it doesn't really matter. I can do what I want.