I have to say, coming back to iRacing last night I personally think the Williams F1 is perhaps the worst car in the sim, I'm sure there are some people that enjoy it but from a sim to real world comparison perspective it's so far from reality in the way it drives and reacts and the way it's driven.
I'm aware the car has the new tyre model, now when I last drove it the car was on the original old tyre model, it feels very similar now actually only the tyres do more unpredictable things and are more sensitive, it's hard to really put into words the exact experience I'm talking about but I guess if you drive it you will understand how it feels and reacts for yourself.
I'm not only finding myself slower than I used to be at iRacing but just slow in general, typically in all the other sims I drive (Rfactor 2, Simraceway, Netkar Pro, Assetto Corsa, GT6, Project Cars) I can jump in and almost immediately feel at home and quickly dial myself in (some more than others, but you get the idea). In iRacing though I feel like I'm constantly at the mercy of unpredictable things happening and strange physics behaviour.
It was suggested that the best car is the Spec Racer Ford... and true to the word it's both very different to how I remember it on the old tyre model and very different to the other experiences I've had in the last day within iRacing... Infact the SRF feels strangely like Assetto Corsa.
Anyway, I feel the learning curve in iRacing is a very strange one, when I joined in 2010 I was much less experienced with sim racing and the quality of sims around at the time was not as high. I must have adapted to iRacing specifically, which is a very different experience to driving other sims, I stopped playing iRacing when the new tyre model was new because to be honest it was a mess.
I came back hoping that the tyre model had been sorted but really if the Williams F1 is anything to go by then they have a lot of work to do, the SRF on the other hand was great, so maybe they are getting there.