In the Le Mans / Audi 2008 documentary "Truth in 24", Alan McNish gives a great corner by corner break down of the track while you follow in-car video.
After playing GT5, I've noticed what appears to be a huge difference in track condition. GT5's Sarthe circuit is amazingly bumpy, especially on the straight, while the actual in-car video doesn't show anything of the severity of what you experience in GT5.
I can't believe the ACO would allow such real-life conditions while being so particular about all their other regulations. Imagine an R10 hitting those bumps at 220 mph for 24 hrs without falling apart, or flying off the track. They did shave that big hill down quite a bit after the Mercedes cars went airborne several years ago.