I would imagine the only wheel officially supported would be their own.
I messed with this about a year or so ago during the beta. Not many tracks at the time, just Zandvoort was available IIRC.
It was clearly based on rFactor, as mentioned, but felt a hell of a lot better, with far better FFB than even Reelfeel.
Yeah completely agree there dude... They have taken the rFactor base to another level now though... Although I don't see it touching CARS or rF2...
On iRacing, keep in mind that many people don't have the time to go through a lengthy career and licensing mode to get to the class of racing they want. Plus the lack of solo play options. iRacing is far from perfect, even without going into the cost factor.
It would be nice to see more next gen sims come out, nothing hits the sweet spot for me yet.
The cost model for iRacing means it has to be the best of the best, and with the amount of downsides it has it can't be called that, especially with what I've seen of the calibre of driving on it... And to pay that much for a game makes no sense to me, especially when it's soon to be out dated...
Plus like was stated, I'd rather spend 5-10 minutes getting the most out of my wheel set up (which on simraceway and rfactor is only a couple of button assignments) than spend hours going through a rookie class filled with crashers just to get to the next tier and race against decent competition...