Would it be unfair to look at AC as competing directly with rf2, and pcars jumping into the console racing space and competing with Forza & GT? I've never played with Pcars but I am trying to get a better fix on who they both are targeting directly. Sure there is crossover but AC doesn't seem likely to go to consoles... So they really need to appeal to the more advanced sim crowd it seems?
I'm quite impressed with this relatively unknown group take such a deep stab at the sim community...
Kunos have a long history in racing sims, starting with NetKar a free sim, and progressing through NetKar Pro, a very hardcore on-line only commercial sim released in 2006, and Ferrari Virtual Academy in 2010. In addition Kunos have worked on simulators for various racing teams.
I don't think AC is competing directly with rF2, and while pCARs main market will be consoles (simply because racing titles sell so much better on consoles than on PCs) I think its a mistake to assume it won't compete with other PC racing sims. SMS staff produced GTR, GT Legends and GTR2, and most of the "investors" came from the PC sim community. As an outsider I get the impression pCARs will be a PC sim ported to consoles rather than the more usual console title ported to PC.
Instead I'd suggest there is a fair degree of overlap between the various sims. ISI have moved from a mod platform rF1 to a much more licensed content centred rF2. AC shares moddability and licensed content with rF2, but is aiming to broaden the appeal by including street cars, a career mode and state of the art graphics. pCARs larger console sales base means it can offer more content as standard which may make the lack of official moddabilty less important. Like AC it also offers street cars, a career mode and state of the art graphics, and along with rF2 offers rain, day/night transition and pitstops. All I will say about physics is IMO all three developers have attempted to do their best to produce the most realistic physics they can, offering aids for those looking for a less hardcore experience. Which title has actually been most successful remains to be seen as none is finalised as yet and its pretty certain ,even when they are finished, sim racers won't agree.
I haven't mentioned iRacing so far, surely the market leader when it comes to on-line racing. None of the new sims has tried to emulate iRacing's system. I think a key reason for this is the main sim market is offline racing, so priority has gone to AI, career modes and moddabilty.
I also think it would be a mistake to count out S3S who seem to be heading firmly in the right direction now and although we seem to be in an era of jack of all trade sims, hopefully there will always be room for niche developers like Reiza.