When it comes to 3D models they always say that it is all about the quality of the texture as opposed to the number of polygons present on the actual model itself. This does not hold true in stereo due to the fact that you can see depth. Now I’m not saying you want to create some billion polygon face but you absolutely must respect all aspects of depth in relation to the model as well as it’s surroundings. Another thing to keep in mind is that your camera is now going to function as virtual eyes. Alot of graphics tricks work in traditional gaming because they are simulating what your eyes would do if you were there. They do not translate well into HMD stereo because you are now simulating your own personal eyes as opposed to looking at a monitor in the distance.
Also keep in mind is that framerate is king. Do not go out of your way to make something look good if it impacts performance. If you plan to go down the road of the DK2 you must respect the fact that you are going to be running high resolution games on a cutting edge engine… not everyone’s computers can handle it at a fluid (+)60fps.
With the way Epic has handled the DK2 I do not see things changing much on our end in terms of the new units. They all basically use different methods to function the same way. I’m confident that the basic functionality of the units will be well documented once they receive official support in UE4. This is of course a shot in the dark as much can change in little time.
Implementing both is not difficult at all but your best option would be controller with the look up and look down removed. You want people to be controlling that aspect with their head as it is much more immersive. Check this post I made in another thread for a more indepth view on basic input: Current VR Game Design Flaws! - XR Development - Epic Developer Community Forums
Figure out if you are going to create a project based off simulation or based off entertainment. If your end game goal is to create something that is basically the new wave of video game entertainment then remember that too much simulation can be a bad thing. No one wants to spend 5-10 seconds reloading a gun in an arcade shooter. Vice versa if you are attempting to create a simulation then nothing is more unimmersive then say “Press B to Open” as opposed to controlling your arms and making them open said object. You have to figure out what it is you want to do then figure out which side of those two spectrums you wish to lean more towards and then respect that choice until completion. If you start out as an “arcade” game then slowly evolve into a simulation then you are going to be doing ALOT of backtracking with your development.