I use ledger to document my personal finances, and I've been using it for about a year.
I do it less for budgeting, and more for a method of centralizing information. I have 4 credit cards that I use regularly, from 3 banks, I'm a w-2 employee with a 401k and benefits, and I file my own taxes. It's hard to keep track of everything, when the relevant data is behind login walls, in occasionally proprietary formats.
I wrote a bunch of scrapers and parsers for obtaining this data, and translating it into a ledger transaction format. Once it's there, I can do all the reporting and whatnot to my heart's content. Writing all of the infrastructure has been a labor of love, with a non-trivial emphasis on labor. I balance out about once a month, but since automating the various transformers, I pretty much never have to debug balances any more, which is a godsend.
It tracks down to a pretty excruciating level of detail, enough that I compute (for example) how much it costs my employer to employ me, my average monthly spread in my checking accounts (between when cc bills, rent are due and when income comes in), average costs of travel-vacation-days, and how that's changed over seasons.
At this point, it mostly "just works", and it's easy to append to my records. The next fun part will be getting useful and actionable insights out of it, and applying them to my life and decisions.
It's very nice to feel "in control" about these things; I don't really worry about money any more.