I driven both hundreds of times (and GTR Evo and FM2-3)- the only difference that I notice between GT4 and SHIFT (when you remove all the other variables- physics and cockpit effects etc.) is right off the start at Hatzenbach. I don't know which of the two is more accurate but the one in SHIFT is bit harder to manouver due to having more bumps.
The climb from Fuchsrohre onto Adenauer Forest seems a bit to steep and short in GT4 and the braking point is different from all the video I've seen of actual driving (ie. Toshio Suzuki in the GTR although the guy's a maniac) while the one in SHIFT is a bit more realistic.
The section from Kallenhard to Wehrseifen has supposedly been paved post GT4 and is much smoother now as is the one in SHIFT. Karussell is definitely much more like the real thing in SHIFT than GT4. All the technical section before the last straightaway look and feel the same. But perhaps due to nature of SHIFT physics, it's more visceral in that game (on the PS3 and the PC version with the G25, don't know much about the 360 version).
As to FM3- I'm happy that T10 has finally narrowed down most of the section from FM2. But the descend and turns at Wehrseifen, seem a bit too mellow as is the following climb. The Karussell is a disaster but the technical section is quite accurate although not as involving as SHIFT. For most part the road also seems too level, bowling alley level- if you look up the climb onto Schwedenkreuz, for example, it should be a bit tilted. Next time, more trees at the start.
http://upload.wikimedia.org/wikipedia/commons/1/10/Nordschleife_image_of_Nurburgring_track.png[IMG][/QUOTE]
Maybe my mistake is to assume GT4's is closer to the real thing. It may or may not be but considering how Kaz is a perfectionist to the point it's nearly sick, I believe it's a safe assumption. What I can tell for sure is that the GT4 version is considerably narrower and bumpier than the Shift version and that the videos I've seen from the real thing also seem to show a narrower and bumpier track. Another thing I can say for sure is that it's a lot more rewarding and fun to drive it on GT4 but that's probably due to physics more than the track layout. Still, the track layout in GT4 appears to be quite more unforgiving. When the real thing is known as "Green Hell", unforgiving is what we are looking for I believe.