I hate to say this but... it would be a real kick in the head if the singular FR vol 4 has all the stuff they didn't include. I seem to have jinxed it now.
I'm still on the fence about this. It's cheaper to get all the volumes like this, and I do like the box. And the risk of S4 not being release (for no apprent reason). But then again, you don't get the books and reproductions you get with the singulars. And what I said... risk of S4 having extra stuff the other doesn't.
Plus, as far as full sets go, I'm puttin' all my money into Ghostbusters.