There are no wrong questions
I guess, there isn't a whole lot difference between the two (a number is a number is a number). Obviously, one is free and another isn't; there are differences in control panel; and if you switch providers you can take your GV number with you - but you already know all that

That said, I can't think of any use case where one would have clear advantage over another. And by the way, if you don't care about the location, IPKall offers free numbers in Washington State that you can forward to VOIPo or many other providers (or even, with some mastery, directly to your adapter).