Regarding the debate about Gran Turismo 5, I feel like it's legit to think that the game has been long overdue for release. All of these new features are nice and all, but they could have put them it in future iterations. Gran Turismo is the type of franchise that each new game replaces its predecessor, unlike say Final Fantasy. So it doesn't need to be delayed infinitely to accommodate for every single idea that Kazunori wakes up to. I find it hard to believe that the game's core mechanic isn't polished to this point unless Polyphony Digital's other other ten projects are preventing it.
To me, GT5 is now GT6. It's as if Polyphony Digital was working on GT 2 and delayed it to the point where it basically became GT 3. I bought both those games and enjoyed them until the new one came out. I can't say the same with GT4 because, well, GT5 isn't here yet and there have been many other options. Are those options better than Gran Turismo? It doesn't matter. We buy and play new games.
After all, Metroid's absence birthed Castlevania and perhaps the same can be said about Shadow Complex.