I own a Vive. Zero motion sickness on room scale games, zero when flying around in Elite:Dangerous. However, get me in something with wheels and it's hell. Rolling in the buggy in Elite is bad, driving in Project Cars is worse.
I've learned that, in Elite, if I look at where the buggy is going (it power slides a lot), then I almost avoid motion sickness. Project Cars, though, I can't play. Cornering, at high speed, completely immersed, with no lateral acceleration, triggers some alarm in me.
VR or no VR, I always play car games from the perspective of the driver's seat or, in some cases, from the front bumper cam. Playing from the third person perspective cam is a bit too arcade for me.
So, my description above is for playing from the driver's seat perspective.
I don't know if it is overblown, but it is certainly real. I've only experience motion sickness under two conditions: helicopter flight on moonless nights, and developing software for the original rift. It was a real bummer, after a few uncomfortable weeks I put it back in the case and haven't touched it since.