I am pleasantly surprised at how Yosemite managed to breathe new life into this thing, making it feel modern, new and very responsive. This is so not like the PC world. Every new iteration of Windows obliterates outdated hardware.
Agreed. I think this is Mac's version of code cleanup, like Microsoft has done with Windows 8 and Windows 10. I distinctly remember my Mac being half as fast with Mountain Lion, and it was still noticeably slower than Yosemite even with the SSD. Everything seems to run blazingly fast in Yosemite. And I think Adobe wrote it's After Effects for Mac because it runs much faster on it than on my PC (same version). My PC still has spinning SATAs though...