Yeah, not meaning to rain on anyone's parade, because this is a good deal - but, it's not a free game, it's a free lease on a game. The lease expires with your subscription and you lose the game. So, yeah, I'd still rather have a physical copy.
I see where you are coming from but I own Gravity Rush (sealed) which I would play and then sell off anyway. So now I can sell it but still have it to play. Plus I'm already a PS+ member so no extra $$$ out of pocket = sweet! The way I look at it is if I play something and it's so amazing I'll want to play it again I can always buy it again and probably at a cheaper price.