I find it extremely disappointing when someone who clearly knows what they are talking about tries to do a bit of a reality check on something that is clearly

I find it extremely disappointing when someone who clearly knows what they are talking about tries to do a bit of a reality check on something that is clearly being uncritically hyped by the press - and then instead of someone actually refuting their arguments they get accused of "naysaying". Yay. As if laws of physics or biology cared about our attempts to circumvent them or trying really really hard/throwing money at the problem. All that it takes is to work hard and sufficient media hype, right? That's not how things work. E.g. people are trying to build "free energy machines" and perpetuum mobiles since centuries ago - so schools teaching that it is not possible are also "naysayers"? I happen to agree with the author of that blog. I have worked in that field for over 20 years, have tried several of those treadmills (probably most of the ones that made rounds in recent years) - and no, they really don't work outside of very niche applications. Sure, one can make them physically work (aka it somewhat lets you move around) - but the movement is very clearly unnatural to the user, you have to "learn" how to walk on them (and get on and off safely!). Without a restraint of some sort (harness, frame, railing, etc.) they are at a major risk of injury too. Running or jumping on these devices is usually a quick way to the hospital. It is simply not at all a practical solution to locomotion in virtual reality. The funny thing is that the Disney project has zero to do with VR and has not even been mentioned in such context in the original article. It is from the "Disney Imagineers" - the folks developing their amusement park rides. There such device has a clear application potential and is certainly a cool piece of engineering.