I never (and maybe wont ever) drove in iRacing, but i just drove a few laps in GPL and i noticed the tires loose traction in a more smooth way. So from what i read, people say that GPL was one of the most realistic sims out there (some say it still is), and i can't say anything about Iracing, but what i'm understanding is that this tire physics rework will make the load/traction curve of the tire more smooth?
I hope i made any sense, its 4a.m. here and i'm with a small headache... gotta go to bed.
PS: when i think about all the equations and variables involved in it... I don't know how Scawen's head hasn't already exploded by the amount of stuff he has to research/write/look at. =D