It's usually not the base system that causes issues. Most instabilities I've come across have to do with distro-specific UI customizations and proprietary add-o

It's usually not the base system that causes issues. Most instabilities I've come across have to do with distro-specific UI customizations and proprietary add-ons such as Flash. For example, Ubuntu Natty Desktop Edition will come with Unity as the default UI, which is a relatively immature platform that Canonical is trying to push hard. Linux Mint will probably stick with GNOME and KDE though. Of course it's always possible to switch to something that is more stable, but that's not exactly "It works out of the box."