Given that I'm currently enjoying an opportunity to do this, I thought I'd share some of what I know, and am discovering, with you guys.
Circumstances left us with an extra flatscreen tv in the house. No you can't have it, and it' only 'decent' quality anyways.
It's a 40 inch sanyo, and I have it sitting on my desk, about 2 feet? or so from my eyes. Just over arms length... I can't quite reach it sticking my arm out without leaning. It sorta feels like I need it to be just a little further away, but I'm running low on room. Thankfully I have a corner desk so I actually have SOME ability to set the thing back from me.
At this distance, it's just barely far enough out. To see the top of the screen, I don't _quite_ have to actually look up, though I'm still wanting to... another few inches of setback would probably be about perfect.
At this distance, 1920x1080p is serviceable, though you can see the 'graininess' in the desktop. It's because I'm too close to the pixels. another few inches probably wont solve this one. I'd probably need at least 6 feet, and maybe as much as 10. Aka, television viewing distance. You gotta have enough range to let the eye start blending the pixels together to get rid of the effect. What's causing it, is the pixels are physically bigger, and the space between them, called dot pitch, is larger.
Reading text isn't really a problem. It's not 'blurry'... again, the 'grain' is noticeable, though it doesnt really interfere with reading.
As far as using the tv is concerned, so far its working. Some tv's end up with excessive 'input lag' between the time the gpu feeds the signal, and the time the tv actually displays it.... This will make itself known as you missing what you thought was a sure shot, say, in battlefield.... because they're actually 50ms ahead of where your tv is displaying them.
Units with a 'pc mode' or dedicated circuity that bypasses all the stuff that makes the tv work properly, will do better.... they can be as fast as a regular monitor if done properly. I also recommend a unit with an LED backlight that can be properly dialed down. TV's are _bright_...
Now, if I could just get this sucker with a 3840x2160 resolution... that... would be nice. Except my GPU would cry and beg me not to play as many games.