He may be right on 2k, but he's wrong on 100in looking bad on 4K. We are talking 8mp and 4x the resolution of 1080p. Are we standing 5ft from the TV and watching a 100+in TV? Most people are at least 8ft from their TV even in a puny apartment you should be close to this. At 6ft+ it should look great. At 12ft with a great rip of 720 (L4.1 ~4000+bitrate total unless DTS add another 1000-1200 depending on 384 or 640 audio comparison) vs 1080 I don't see much difference with 60in. Move in about 3-4 more feet though and I start to want 1080p. I have 20/15 vision (lasik). There is a difference, but it's not like the change from dvd to bluray. The trade off of file size vs. gain in quality isn't worth it for us at 60 (for tv shows, I do some movies in 1080p), but I'm wondering if I will wish I'd went 1080p for everything now that I'm pondering a 70+.
The chart linked below says you'll see 720p tap out at 70in at around 13.5 (which may be ok in a 17-18ft living room). At 75in it says you'll need to be about 14.5+ away with 720p. If that's correct I may be thinking my 720p's are looking like dvds soon...LOL.
Optimal viewing distance for 100in 4K is 6-13ft. I'm guessing 120in would push both numbers out 2ft but not much more based on the chart.
http
/theosroundtable.com/andrew-robinson/andrew-robinson-too-close-4ks-effect-on-viewers-viewing-distances/
That image is all over on google, I just picked a place. Like I said, are you sitting at 5ft? How close do you need to be, and how hard is it to watch TV where you have to look left and right to see the whole thing? LOL. Personally I don't want to be closer than 8ft and have no room in the house where that would happen.