It comes down to choosing the lesser of multiple evils. Something like Debian with 'stable' repositories is great for only getting necessary updates, but then you lack the newest releases with the wet paint. On the other hand, use a Fedora to get those releases, but get yourself some occasional trouble with conflicts (I had a broken BIND back in February - ouch!). It's no different from Microsoft Update in that respect, except 'only' your OS is broken there if a quick update goes wrong.
By the way, with Mandriva you can use urpmi and select only security/bug-fix updates. It's a good tool for a good distro. For work, though, I prefer the Debian Way of everything just working together.