Wrote one of those many years ago, yes - for medical data. It's the right solution to just about every problem actually, and I'm surprised that it isn't more commonly taught.
One thing I haven't figured out is how to archive old records, I think it's not a problem for modern DBMSs, but we have a problem at work with 15 years' worth of historical data.
Works great. Especially for anything that needs history, e.g. medical data.