Good read, thanks for posting.
I also like to keep the older equipment running. My wife has my old late-2008 MBP, that she uses daily. That has an SSD and RAM upgrades. The misses was complaining that the machine was running slow, so I put in the SSD and removed a whole bunch of crappy browser extensions. BAM - whole "new" machine.
And my son plays minecraft on my old 2006 - 1.83 CoreDuo. Only a memory and battery upgrade there.