There isn't an OS on the planet that will ever take up 500GB. In fact my laptop only has a 250GB drive and that not only handles my OS, but also all my program data and program files just fine, and I have 100GB left over.
I recommend just the opposite as this person. Put your OS on the SSD, even if its small, and move everything else to a slower drive.
you didn't read the quote did you?