Raises hand.
I mostly got over motion sickness with my old VFX1. Never for Descent II though. It is about software more then anything. Up should remain up. Heli and driving sims work pretty good. Fixed wing less so. 3d shooters are OK but the devil is in the details.
In my experience the DK2 is no better then the VFX1 for motion sickness (Both working side by side). When the VFX1 shipped it was terrible, but once the VFX1 was running on a GHz processor and refreshing at 200fps, which is much faster then it's old interleaved 30Hz screen, it became OK.
The problem people working the motion sickness problem face is they are naturally being desensitized. So whatever they think will help with nausea does.
That said: I never get motion sick IRL. VR has mostly been no big issue. Two exceptions: Descent II (VFX1) and Alien Isolation (DK2, I have no explanation for why Alien Isolation is so bad, but it's very pukey. Still not hours for recovery, but 15 minute gaming limit.)