Retired IT, playing with Ubuntu every day. I had great troubles with the UEFI when installing 13.04 8 months ago, but it has worked since then very nicely.

A recent addition of software messed up the 13.04 system, so I decided to do an install (not an upgrade) of 13.10. OOOooops...

I dumped Win 7 3 years ago for Ubuntu, and have had a lot fewer issues to fix each month.