The main reason I favour the availability of a canned package (be it source or binary based), is because the tools can easily tell me when updates are available, and just how far out of date I am. --> As opposed to doing it manually or "when only strictly necessary", in which case I'd use CentOS RPMs.
When I need something, I usually make a package for the OS I'm using, or I install it by hand. I've got a number of things installed into ~/Software.
Thou shalt check the array bounds of all strings (indeed, all arrays), for surely where thou typest ``foo'' someone someday shall type ``supercalifragilisticexpialidocious''.