>Definitely correct, the issue is when you're trying to install a package to get something done, and suddenly your faced with the proposition of either upgrading your whole system while trying to get work done or attempting to upgrade just the required libraries. The latter often carries less risk, but occasionally is very problematic.

I may be wrong, as my default is to -Syu any package I install, but doesn't -S install the version of the package compatible with the last time you updated your repos? It's -Sy that can cause problems.