3 Commando Brigade

GTA V Virtuix Omni

That looks pretty horrible, actually.
See how he's constantly looking and pointing his gun downwards in real life, even when he's aiming perfectly flat in-game? That massive disconnect would bug the hell out of me.

None of the "full-body" VR solution are even close to good enough to consider dropping a few thousand dollar on. The best experience possible today would probably be achieved by going to a more "arcade" style of gaming: 
You go to the "arcade", pay money to play and then get to go into a large room where a mocap setup tracks you and your gun. The game would be custom made to the room, with the room featuring plywood/foam "walls" that match the in-game map. Add in a high-bandwith wireless setup so that you can beam images from a large (think 'tiny supercomputer') renderfarm that's located on the premises to a VR headset. Because of the extreme cost and the "one map => one real life stage" constraints, it would have to be an arcade that you go to, rather than something you have at home (unless you're stupidly rich).

Constructing a sort of 'physics LOD' of the virtual world in real life currently seems to be the only way to allow you to e.g. slide around/press up against cover/etc. 

Unless somebody makes a breakthrough invention in advanced force-feedback clothing, I simply don't quite see a 'moving in one spot" solution being anywhere near immersive.

I'm saying this because I've noticed that the omni developers seem to be very unconcerned with the massive problems in their product. 
The original concept is pretty cool: Low-friction surfaces are definitively the future for in-place "treadmill" style things. and their harness seems solid -- it apparently carried most of that guys weight when he was driving, so that's pretty cool.

But: Their approach to input/tracking is completely off. They use special shoes to "track" your movement, which means it's more like pressing buttons mounted under your shoes. So the whole "walking" isn't anywhere near as direct as they pretend.
The same apparently goes for the gun: looks like it uses inertial tracking -- he doesn't even properly shoulder it before he fires. Again, it's more like waving around a Wii-mote.

If they added a motion tracking system (e.g. a few cameras + track points on your feet, upperbody and gun) they could create a really accurate and immersive experience.
Instead they seem to be more focussed on generating publicity by showing people play games that aren't even remotely designed for VR with a system that's essentially just a really clunky xbox controller.