Me? Haha no. It's just Macs always function more smoothly with their native OS.
When you pay the sick premium for OSX on Mac hardware you're shooting yourself in the foot running something like Linux on it instead.
OMG, I need a proper rolling around laughing emoticon!
Macs also don't always 'function more smoothly' with their native OS, I've never heard such tripe
Also, there are many other things which come into play when buying a computer, just for example the aesthetics of a Mac are generally considered to be extremely good. A classic case of OSX can do no wrong syndrome I think.
Back onto the Linux topic, most stuff will continue working if you upgrade Ubuntu, with no problems at all- Anything out of the stock repositories (I.E. Not compiled from source), and most deb installed stuff will carry on as normal. Restricted drivers etc. will also be upgraded with the base OS.
Some settings etc. may be reset, but this is the exception, not the rule

Things compiled from source may or may not work, all depends on how flexible they are with dependancies.
The beta versions are a different kettle of fish- Most of the time they'll work with no problems at all, but occasionally there is a system breaking bug. Basically, if you're not comfortable with rebuilding stuff from source and mucking about on the command line then the beta's probably aren't for you.
-Leezer-