It has definitely come a long way but definitely seems to have an issue with being slightly too fast in high speed sections and slightly too slow in low speed sections.
I agree, the AI in rfactor 2 is really ahead of the competition, It's the only AI that I can have fun with. The Ai in assetto is probably the worst of all the sims, it's comical when you have a multi class race and they can't even overtake slower cars, they stay behind the entire race. I still play a lot of assetto because the feeling when driving a street car in a circuit is really good, I have driven a ferrari f430 in a circuit, and the force feedback is really good in that sim.
Pretty much any offline race in AC using the AI is a complete mess at this point imo. At this point I'm inclined to just leave it for a year, come back and hope it has improved by then. Cars breaking down left right and center, AI not overtaking no matter how slow you go. Ramming you off the road, and not being affected by the impact (like a tank glued to the track), continuing down the road as if nothing happened. AI never makes "human" mistakes, the mistakes it makes are just glitchy and buggy, completely immersion breaking. The changelog keeps reading "AI improvements" but the bitter truth is that it's still pretty much useless, sadly. I won't go near online racing in AC, so that pretty much leaves me with a hotlap simulator... and I don't have much use of a hotlap simulator... The AI in R3E is way more enjoyable than AC's, I find. They're somewhat capable of side-by side racing, occasionally makes human mistakes, they don't ram you off the road, etc. They aren't hesitant when overtaking either, which makes for some pretty entertaining offline races imo. Besides rF2 of course, R3E is the sim to watch imo, if you're into great offline racing.
Another advantage that rFactor and rFactor 2 have is that you can add AI to online races, but you can't do that in Assetto Corsa.
True but it was quite funny once when I joined a server and started asking for set ups and making conversation with the 5 ai, only to leave thinking how rude and ignorant they all were lol