On the one hand, I understand where you both are coming from. 'Real-world' performance is where the rubber meets the road, so to speak!
But on the other hand, without some type of objective analysis, how are potential buyers going to decide between purchasing an NX7 over an NX5, or an NX9 over any NX7, or even a Z1 over the NX9??
Simply relying on any Projector owner to report, "Man, this looks great!" is of no use whatsoever to me, or others, as potential buyers, especially since most of these have not been in a position to do controlled, side-by-side comparisons with other Projectors.
And if the various specifications, and their actual measurements, do not correlate well with that 'real-world' performance, then we're really up the creek.
The only remaining way to provide objective data for buyers would then by fully controlled, calibrated, brightness-matched, side-by-side comparisons, of the various Projectors, done by competent folks like @ARROW-AV; , @Kris Deering; , etc., who would be among the extremely rare group of people with the talent, skills, tools, and opportunity to perform such comparisons.
And even then, quantifying their observations, which are ultimately subjective, is also problematic. Perhaps if they could include some type of double-blinded polling by home theater enthusiasts they could invite over, to try and assess whether those differences are consistently observable, along with their characterizations of the differences they're seeing, we might get some legitimate basis for decision making.