Vulcan can answer that best I'm sure, I have similar questions, as I use TiR when just tooling around in AH, but flip it off due to A, my thumb/hat views being faster and more natural due to time I guess, and B, my neck probably feeling something like yours when turning it around too much.
Vulcan IIRC has said he uses some sort of "track" thing WITH the DK2, I don't think it does it all on its own, but having not messed with it, I'm just going by what I understood from what he's said, he'll certainly explain it better than I can, and I'd like some more info too on the DK2 use as they are VERY cheap right now with guys dumping them, and I'm still holding off on ordering both the Vive and Rift to see if it's something I really want to use. All the work HTC is doing and Vulcan's initial posts already have me considering getting in line now for rift.