Back when Ubuntu first sported home folder encryption (what, around the time of Jaunty Jackalope?), I opted in. That caused me some grief when I decided to change my login password. I found that I couldn't decrypt my home anymore! In trying to fix this, I eventually muddled things to the point that using my old password didn't work anymore, either.
That experience has left me very shy of using an encrypted home directory--nevermind the performance hit of encryption. Has this feature become more "stable" since it came out? Does it break if you change your login password? Has your [more recent] experience been better? (Does it work in Natty Narwhal?)