to summarise, the Vive wins at roomscale. For anything else, get WMR for like 200 off ebay (new).
I beg to disagree here. The Oculus Touch controllers are so much better than any other currently available VR controllers that they make the Oculus by far the best interactive experience in VR. Just being able to use simple gestures like finger pointing, thumbs up, waving, and naturally using a gripping motion to pick things up is so much more immersive than the wand style controllers other systems use.
When the Vive gets the Knuckle controllers, then that may change.
Though if all you want to do is Sim Racing or Flight/Space Sims then a WMR headset is a good idea due to not needing external sensors/lighthouses, but only if you get a WMR headset with higher resolution LCD/OLED panels, as the Rift lenses and panels generally give a clearer image with a larger in-focus sweet spot than the other WMR headsets.