Besides being a mathematician and a programmer, I have a degree in finance and banking, so I learned double-entry accounting pretty early. As a mathematician, I appreciate the beauty of this very clever, very general and very abstract system. As a geek, I've been using ledger-cli with Emacs for a decade now, and Gnucash earlier.

Re: learning curve, it's not that difficult. Shameless plug: I wrote a textbook (actually, a textbooklet, if that is a word;-)) about the basics of DEA, focused on personal finance and using ledger-cli: https://leanpub.com/personal-accounting-in-ledger/