Re: Am I missing the point here?
A 55" telly at a dozen feet is about the same size as a Galaxy S5 viewed at 13.3 inches, an iPhone 5S at 10.5 inches or an HTC One (M8) at 13 inches.
Of course that means at that at 12 feet even the lowly 1080p 55" telly has a "retina" display so I'm not really getting the point of these 4 & 5K resolutions these guys are selling. Consider that the aforementioned 55" telly viewed from 144 inches has roughly 105 pixels per degree of arc. For the sake of completion, at the distances above the respective phones are 105, 62.5 and 104.7 pixels per degree.
Equating that 105 pixels per degree angular resolution to the 105" 5K set gives a viewing distance of only 80 inches. If we buy into the premise that the "average" human eye doesn't resolve pixels at a higher density than that it means the extra resolution is wasted beyond 80 inches. Of course 80 inches is likely a silly distance to view a 105" screen as it would appear to be roughly the same size as the iPhone screen held a mere 3 inches from your face - which isn't to say one could focus on the iPhone at that distance, I know I couldn't.