An interesting concept to be sure that should be easy for other manufacturers to adopt using their CAD software. Kudos to Nemo for adapting it across their entire shelter line rather than just on select models. That's a gutsy marketing move.
However, Is this just clever marketing hype or truly meaningful and useful information for the consumer?
This looks like a two-edged sword for manufacturers. On the one hand, it's a great sales tool for those shelters that boast of their headroom advantage over Brand X, but a probable sales killer for some other items in their line-up where floor area and peak height look good but where useable headspace is poor.
Standardization on the height of the human occupant being used (good luck with that) would be necessary in order to make reasonable comparisons between manufacturers.
I'd like to hear the views of other manufacturers like Henry at Tarptent, Ron at Six Moon Designs, Ron at Mtn Laurel Designs, and Joe at Zpacks. The big boys - TNF, Marmot, Hilleberg, etc., will jump on it only if it looks like it might be a good sales tool.