I guess one or two people would disagree on the genius part, but thanks anyway.
To be sure the (laggy) vorpX gamepad stick emulation is really disabled, go the gamepad page of the vorpX ingame menu and set the “Head Tracking As Gamepad” option to “Off”. Judging from a short test there seems to be a glitch that sometimes still applies that despite head tracking being disabled.
Apart from that turning off FluidSync (display page of the vorpX menu) helps if your PC is fast enough to run the game at 90fps.
If you do the above, everything should be OK. In direct comparison there maybe is a tiny little bit more latency on Vive than on Rift, but I’m not really sure. Both are working quite well here with OpenTrack in Dirt 3.