Just a few comments:
1. The side by side video is from Suzuka. The Japanese Grand Prix was at Fuji in 2007 so the real life image must be from, at the latest, 2006. So, even if GT5p was spot on there would be some differences.
2. In 2007 F1 had traction control. Some drivers used it more than others but I don't know if that explains why people feel it's still on when they turned it off. Assuming it's always on it did reduce over-steer on corner exit, in real life. Well, they had all kinds of gizmos and engine breaking tricks last year!
3. In terms of realism: The cars change a huge amount throughout the season, with special pieces for individual tracks, different engine maps (how that works with the common ECU this year, I don't know), different gearing and so on. Even within one team different drivers may use different bits or have the differential set differently. What I'm trying to say is that in GT5p they had to find a way to translate that into one car for all tracks, so it's bound to be a compromise.
4. On the subject of teams using simulators. From a friend working for an F1 team, I understand that there are simulators available to the drivers but only some use them and even then its mostly to get an idea of new tracks. For development the simulations are run without a "driver" and tend to focus on single components, so to model a new suspension change, for example.
5. Of course there's the way an F1 car can only really be driven hard which doesn't seem to modelled at all (a previous poster touched on that).
Personally I've been playing F1, F3000 racing games since the 80s and have never found any really get it right. I'm also not sure that driving an F1 car is hat much fun, I think I prefer touring cars......
Anyway, just an opinion to add to the debate :-)