I had a really bad experience with the 1.2.x series of LedgerSMB when I was running my business on it about 4 years ago. Invoices couldn't be reprinted accurately if the sales tax rate changed, and it didn't handle foreign currencies well. My accountant really wasn't happy when I couldn't produce an general ledger report and trial balance that added up to the same values. I haven't looked at the 1.3.x series, so things may be better now.
I switched from that to Postbooks which has worked extremely well. I particularly like that the database logic is implemented as Postgresql stored procedures which means it is safe to use other applications to manipulate the data (like to import transactions). I back the whole thing up with a plain-text dump of the database stored in a git tree. Most importantly, I've not had a complaint from my accountant since. :-)