Apparently right enough for professional race car drivers to use it for practice and preparation.
"I don't like it" does not equal "it's wrong".
i never trust that "race drivers use it". the same has been said for granturismo or forza and the f1 series. Well my thoughts on simulation are very very strict hence my shunning of project cars. While it does some things right they mess up big time in other areas. The bottom line however regardless of how we twist things is that there are flaws in the physics model of project cars sadly its hard to judge this as the raw calculations themselves arent available to the public.
Let me put it this way, if i wish to mod in AC, RF2, automobilista etc then i can directly just shove numbers from telemetry into the files and it will work more or less with a few tweaks.
Pcars isnt like that, i gave up quickly because i didnt want to face this problem again, assetto corsa used to have it because camber, suspension and tyre friction curves were odd, they didnt work as a result tyre temps wouldnt heat up enough, pars currently has this issue and then bump stops are quite edgy which is a massive problem for suspension. most cars are designed to be predictable, people dont like surprises, pcars gives you surprises. its like telling you to do 5 laps or so around brands hatch, taking a break and then doing another five laps but someone has ripped off your dive planes and maxed out the psi on your rear tyres so all of a sudden you are experiencing oversteer.
The problem then is that you have to make a solution if real numbers dont work which is down to "it feels right". Now you have no idea if what you are doing feels right or not.
My bias comes from me being a modder so ill always be tinkering with the numbers but i try and be as real as i can however having to guess majorly jeopardises that.
This is all just my opinion though, i respect what you think but it would be nice if they would fix their flaws.