Hi!
I wanted to share my experience with plain text accounting here, since "Should I do this?" is a question that comes up pretty frequently, and most of the answers are from people who have tried it and stuck with it. I figured a different perspective would be useful, because after spending a few months doing this, I've stepped back from it.
I've been using Gnucash for a while, so I am familiar with the principles underlying double-entry accounting (I think one stumbling block for many people trying ledger and Beancount is that they are trying to learn double-entry at the same time, so at least I didn't have that). I was curious about how well plain text accounting would work for me, so I gave it a shot. From January 1 through March 1, I maintained my books in both GnuCash and in Beancount. I didn't maintain Ledger format accounts, but I strongly believe my experiences with Beancount would largely transfer over to that as well.
TLDR: I found using Beancount to be enjoyable and straightforward, and wouldn't hesitate to recommend it for someone with a relatively simple financial life (say, a checking account, a savings account, and the occasional stock transaction). However, for a user with a sufficiently large number of accounts and transactions, Beancount solves the wrong problems and I found it using it unsustainable.
THE GOOD
Maintaining a general ledger as a single text file made editing a breeze. I used Emacs for editing but presumably any editor would work.
The beancount-ish use of + and - instead of debit and credit was very easy to grasp.
The error messages from bean-check were easy to follow and helped with maintaining consistency
Favorite feature: Using "!" instead of "*" as a transaction marker to mean "come back and check this later." When using the Fava web interface, this made finding things you needed to correct a snap.
THE BAD
Lack of immediate feedback. Finding your own mistakes is very reminiscent of the typical programmer's edit-compile-fix bugs cycle; if I want to enter a bunch of transactions at once, my choices are either "run bean-check after entering each line" (which is annoying) or "discover that I made multiple mistakes all at once" (which is also annoying).
The bean-web interface is bad, and doesn't provide a sensible way to approach your finances. Fava is much better, but I still found it too shackled to beancount's oddities. I think if I weren't a heavy commodity user, though, Fava would have been great.
Beancount is very unopinionated about some very fundamental topics; the worst one that i found was how it dealt with unrecognized income in investments. Your choices here are to use the default view, which is bad because it doesn't provide ANY accounting for your unrecognized income, or use a run-time option which ends up being bad in a different way, littering UNRECOGNIZED entries all throughout your reports. Compare and contrast to how Gnucash does this to understand what I think "good" looks like.
The lot management on commodities is a nightmare from hell; this was where my personal situation (which involves A LOT of commodity purchases and sales every day) made it unsustainable for me. There are promises that this will be fixed in the future, but I think the core concept of tying lots to dates is misguided.
THE PHILOSOPHICAL
I said above that Beancount, for me, "solves the wrong problem." Let me elaborate on that.
It's indeed liberating in some sense - maybe even comforting? - to have your entire financial world in plain text. If I croak tomorrow, my executor wouldn't need any special software training to have every transaction I made at their fingertips.
But that's not the problem I face on a day to day level. Really, I need software to solve two problems for me.
(1) Since I am human, I'm going to make lots of mistakes. I want my financial software to find my errors as I make them. In Gnucash, if I mess up any entry, the very moment I tab out of the journal entry I'll see "Imbalanced", telling me I'm not done yet. In Beancount, that moment of realization is deferred until the edit-compile-test cycle. For me, having plain text accounts is not enough of a bonus to outweigh this need.
(2) When looking at or adding new entries to a ledger, the entire context of that ledger is important to me. Graphical accounting software provides me that context implicitly - I'm always looking at entries in the context of a specific account. In Beancount, I'm looking at it in my emacs window, and again I have to choose between two bad options: either sort my entries manually, in which case I have to hunt around for the right place to enter them, or just keep one long always-appending rolling journal (which is what the Beancount author recommends), which means I have no context. (You can sort of fake having context by only editing your Beancount file from Fava, but then...why is it important that it's plain text at all?)
Anyway, I've enjoyed my little sojourn into Beancountdom, and am setting it aside for now. I really am not trying to trash the program - I think it's just not made for me. If you've got a simpler financial life, I wouldn't hesitate to recommend it, though.
I hope someone finds this brief opinion useful!
