Nice tool, fits with my experiences.
My TV and my projection screen are 2 - 3 meters (6 - 10 feet) away, depends on the seating position.
Blu-ray movies + PS4 games on the 77'' projection screen from the 3 meter distance couldn't be better. From the 2 meter distance they still look great, but could profit from 4K... but without affordable 4K-content (movies and games) I will wait another few years before upgrading my projector.
The same goes for PS3 + 360 + Wii U games on my 47''-TV: flawless from the 3 meter distance, but only "okay" from the 2 meter position. PS2 games (on my PS3) and Wii games (on my Wii U) aren't a pretty sight anymore, especially from 2 meter distance... the resolution above is even a bit sugarcoated, since it's anamophic 640 x 480 stretched to 853 x 480.
The distance to my PC screen varies between 60 - 120 cm (2 - 4 feet)... if I use a gamepad I'm sitting a bit further away. 2560 x 1600 would be nice, but I would need a much faster graphic card for that.
Usually I'm holding my handhelds in a distance between 30 - 40 cm. The Vita screen looks flawless in that distance (some Vita games with sub-native resolution show some pixels), but on every other handheld (and of course PSP + PS1 games on the Vita) you can see the pixel structure. Don't get me wrong, the games are still great fun and while playing I forget the resolution issues most time... but now and then it breaks the immersion.
Moving on to my other mobile devices. I'm still happy with the "ancient" 960x540 resolution of my smartphone, I don't get the 1080p models and higher. Like handhelds, I use it in a eye distance of 30 - 40 cm... perhaps I'm "holding it wrong" and I'm supposed to hold it in 20 cm distance. Tablets i keep a bit farther away (35 - 50 cm)... my first iPad was a bit blurry in that distance, both my Kindle Fire HD7 and my iPad Air look flawless in normal distance.
