The biggest gotcha that I see is restoring backups. According to the article, for that you need to have the actual long passphrase used internally, and not your regular password. So when you're in trouble you need to come up with a critical piece of information that you never use and probably don't know. That's going to bite more than a few people at a bad time.
RE the long passphrase: Need to write it down and put it in the safe deposit box at the bank. But not too many people do that (I don't think). I know I didn't do it. And now that you mention it, I can't remember my long passphrase. Crap.
Another gotcha would be that it would be difficult to rescue since the ubuntu livecd doesn't have that app by default and I don't know of any livecds that do
I saw that they used apt to install it, so I would imagine that it doesn't have it installed by default. Also not all livecds would have it so you would have to depend on the ubuntu livecd
Otherwise it looks excellent.