That's not true for Linux - I've had many instances where repo refs broke because they didn't have packages for updated version, or where the new version kernel introduced a bug breaking my WiFi, audio, graphics, or random stuff failing - it's probably worse than doing a Windows upgrade.

I've only used macs for a year and only did 10.5 -> 10.6 which went smooth IIRC. Mac approach of owning the hardware and the OS certainly has it's advantage - being able to clone image to an external HDD from my MB pro and then boot a iMac to the exact same image is a magical experience. Setting up a master image on my laptop and then redeploying to an office of 40 something various mac devices using IP broadcast and doing it in an hour - hearing that apple chime 40 times was really cool :D

I had a spectaculr Ubuntu LTS upgrade failure on a server earlier this year because I had inadvertently left a terminal open running a command with 'su'.

It transpires that the sudo binary cannot be upgraded when su is active, so the entire upgrade cascade-failed and left me with a broken and unbootable system. Had to start from bare-metal.