Lag? What lag?
1. The lag everyone keeps talking about where the framerate dips to 'unplayable levels' hasn't happened to me. At all. I've beaten Episode One and Portal already, and it has never gotten like that.
2. The longer loading times aren't an issue at all. It's about 5 second to quick-load instead of 2. Big deal.
All in all, if you own a PS3, you owe it to yourself to play this game. Don't believe the gamespot review for it talking about the 'slideshow-like framerate', because that just doesn't happen.