The lag is a result of shoddy coding and complete lack of testing on Bethesda's side, I can assure you it's not because how your PS3 is hooked to your TV or what settings it uses.
It clearly is not as black and white as you make it sound, otherwise EVERYONE would be experiencing these issues.
Play time isn't what's important. It's file size. Have you reached 6.3 MB yet?
First it was 5000kb, then 6000kb, and now 6300kb? Why must those that are experiencing lag feel the need to personally guarantee we will eventually get lagged out? It was the same for me with FO3... all these threads about the game being absolutely unplayable on the PS3, and I completed the game with a total of 3 freezes that required a reset, and that was
it.