Well, I got a chance to try my son's Vive Cosmos VR setup with DCS this afternoon. After downloading/installing/setting up the Cosmos on my machine, I'm pretty sure my computer weighed more.
Anyway, wow, that was awesome. I think I experienced a touch of motion sickness while flying - briefly. I wasn't able to use Cosmos VR handstick things to fly and push buttons in the cockpit, rather I flew with the X52 and just used the VR headset for viewing. I did a take off and landing and it was soooo much easier to just look around and see the surrounding area and the runway.
Definitely need a HOTAS to fly still, and you need to have the controls memorized by touch.
Was it awesome enough to make me want to buy one? I actually don't think so. I really think having IR head tracking and my 35" curved monitor might be a better overall experience for *me*. I'm still at the stage where I need to follow written instructions to successfully attack any targets in DCS and having that second monitor with a guide open is kind of critical for me.
So I think I'll go in the direction of getting a TrackIR, and then consider upgrading to a TM Warthog.
EDIT: Also, if you want to try VR on the cheap, there is a Steam VR thing called iVRy - it uses your phone and a cheap VR headset (you can often get them for $1 on clearance at walmart). It's not great with DCS, in fact, I'd say it's not even good for DCS, but it does work).