So much of this is demonstrably untrue, PD have moved their physics game along to the point its reasonable. However the damper, aero and tyre model still lag behind.The Collector's Edition.
It is unlikely to be easy to get good quality data and everything you need for all the cars in the game. Some games feel like you are actually just driving the data rather than a simulation. PDI's approach seems to be that of creating a perfect simulator. Although it is impossible, it gives plenty of scope to improve to become much closer to real. Even centuries later it will probably still be far from ideal. However you can still get good characteristics in a abstract way already and that level should improve greatly by over the next decade given improvements in CPU performance which will allow developers to express themselves better. Fortunately we still live in an era where we can still drive the real cars with combustion engines, if only it wasn't so costly compared to virtual.
Hamilton reached out to them, it is clear that he can drive quite well in the game straightaway so must be natural enough for him to adjust to. Also he can direct areas of the game to be better, read the setup of W08 will be improved. Great person for PDI to have on board given his experience with the real thing and bespoke F1 simulators and directing them to be more realistic. Also heard Toyota drivers which consist of F1 drivers in the past like Kobayashi and Alonso played GT Sport a lot while at Le Mans 2018. Good timing of the 1.19 update by PDI, played a part in Toyota's first Le Mans victory and 1-2.
I think in the future there may be cases that the GT engine will be used by F1 teams. Drivers themselves use GT Sport to practice and keep themselves sharp like Hamilton and Ocon. Nvidia used GT engine for self driving cars development so already a rival to rFactor Pro in that regard. Slowly but surely one day PDI will have all / most of the current F1 tracks in the game so should make GT a very attractive package having super realistic graphics (Good way to utilise their ray tracing system) and accuracy of tracks which is most realistic part of a sim. Teams would use their own data and likely physics model though as they know better in detail how everything works for their specific car which will likely be top secret information.
GT simulates wheel spin, probably if the physics engine ran at a faster rate and mapping was changed a little bit it would be easier to modulate even with current model. Longitudinal grip exists and is plentiful, just need to have fine throttle control which is not necessarily a bad thing for a simulator to teach a driver. It is quite satisfying nailing traction out of a corner unlike a lot of other sims where there is little skill involved. LFS is probably more of an arcade game than Driveclub, it has a lot less advanced physics engine either way. Passable back in 2003 though as a sim. Then you have more complex sim like rFactor 2 and they seemed to have simulated a black hole in their tyre model the way cars seem to slide instead of losing control as one would expect when you overcook a corner too much.
Aero like I said before is where I think GT is ahead of all PC sims regarding physics. It must be quite taxing having such an advanced system in the game with such a low end CPU that already has to process so much in the game such as the graphics and sound simulation. Cars feel like on the knife-edge at the aerodynamic limits which is fun unlike how dull it is in AC. Also your description of ACC aero model is actually the way they did it for AC regarding wings IIRC which was terrible. ACC is like GTS approach but seems a lot less advanced. The effect in driving is very much like AC though, they seemed to have retained that concrete rear end feeling of AC while driving but any sort of big suspension movement even at really low speed, it is almost like someone is performing a pit manoeuvre. It is quite similar to how it is in the F1 games. The cars still feel like they aren't under any aerodynamic load so doesn't surprise me that it seems braking technique is of that of a street car unlike GT Sport. Low speed physics in ACC does not feel right but they seem more like they are trying to simulate it unlike AC. Does not feel fun to drive but still a bargain for number of good quality tracks you get.
They exist and people use them on GT Sport already but what I had in mind was getting it so that it is mainstream. If the DS5 and next Logitech and Thrustmaster wheels have it then that is massive improvement in realism. PS4 isn't a great platform for FFB due to latency and low CPU performance not allowing for more complex physics to run at a decent frequency. Feedback will massively improve with GT with better hardware as they seem to have the realistic approach regarding FFB. Older wheels used to work good in older GTs but now it seems like almost a no compromise approach regarding force feedback that requires the wheel to be able to have the dynamic range and response with platform to give a realistic feeling. AC FFB feels quite amplified, you can feel it even on controller like Xbox 360.
Aero loading in particular has some clear issues.
F1 teams will never use GT as a platform, and if you look at motorsports grade simulations visuals are way down the priority list, and the likes of Ferrari, Mercedes and Porsche went in a different direction for experience centre simulators.
GT is great fun, but it's not a match for the likes of AC or even PC2 in terms of physics, and that's a quite clear design choice on PDs part.
GTS issues with load transfer can be experienced by doing back to backs quite easily, simply take the original Fiat 500 out around a track induce heavy understeer and then lift off the throttle sharply. In GTS you will simply slow down the degree that you are washing out, what should happen (in a stupidly light, shortwheel base, RR engined car with all its weight at the rear) is a rapid transition to lift off oversteer, and heavy lift off oversteer at that. AC models this very, very well.
Its the same with race prep'd FWD cars (and some road ones as well), GTS gives you a decrease in understeer when you lift off, when it should be a rapid transition to liftoff oversteer. Add in the lack of aggression from the diffs you have on these cars and in reality you should be able to lift off to get the back out, point in the right direction and hammer the throttle to drag the car around. which is exactly how they are driven in reality, and exactly how you drive them in AC and PC2, yet it simply doesn't work in GTS (and no amount of tuning of the cars will make it happen either).
Oh and the magic FFB with the TGT, it's a tactile Puck that's fed by GTS added into the wheel. You can get a better range of tactile feedback, across more titles, for less money with a standalone tactile setup (and if real accuracy in this regard is your end goal then simvibe on PC wipes the floor with it).
However once again it easy to experience the difference in FFB between GTS and other titles. Take any car to Brands Hatch (either layout) and end the first turn at a reasonable speed. Paddock Hill has a pronounced drop off, and the car on the racing line is not running parallel to the road. As such you should be able, through the FFB, to feel the left and right wheels load and unload, and it should be subtle enough that you can keep it under control simply by changing the amount of pressure in your wrists very slightly. Once again you get this in both PC2 and AC (with AC being better in this regard), GTS you get nothing at all.
Now don't get me wrong, I'm in a place that I really, really like GTS; but I'm also quite aware of the limits it has in regard to its physics engine and tyre model.