THX recommended viewing distances
In box number 1 on page 78 of the January 2013 issue of What Hi-Fi Sound and Vision the THX recommendations for viewing distances are given as 3-5 ft for a 35-inch screen, 4-6 ft for a 40-inch screen, 5-7.5 ft for a 50-inch screen and 6-9 ft for a 60-inch screen. I have two questions:
1. Do forum people agree with these distances?
2. Do forum people actually follow these guidelines in their own homes?
In my case, I do agree with these distances, I don't think that they are too close. To answer the second question, no, I don't quite follow them myself, because of practicality. In my parlour I mostly watch from the computer which is level with the middle row of seats, about 12 ft to my 64" Samsung, though the sofa is nine feet from the TV and the back row of bar stools is 15 feet away. In the kitchen I now have a 60" LG60PZ950T plasma, and when cooking or ironing or washing clothes I'm about 13 feet away. When I run films shows, in the kitchen I temporarily set up three rows of seats, ranging from seven feet to 13 feet away from the screen. In the bedroom, from the bed itself I'm about seven feet from my 42" Pioneer, and the row of six seats behind the bed are 10 feet from the screen.
So, what do peoople think of the THX recommended viewing distances, and what do people actually do?
No arguments from here. I would add however that these guidlines are for cinema/film. I think they apply less to day to day tele'.
Bear in mind that these distances are for HD content only. When I demoed the 60-inch Kuro at my viewing distance (9 feet), my eyes were finding it hard to get adjusted to fast motion.
Whatever the experts say, trust your eyes before making a purchase.
Sit as close as you like - regardless of how many times our mothers told us, none of us have square eyes 
For some reason I don't often seem to be too affected whether watching HD or SD at the viewing distances in my rooms; I seldom think that I'm too close when watching SD, even when looking at fast motion, maybe it's just my insensitve eyes - in keeping with the rest of me! In fact sometimes I think that some of the Channel 5 group of SD programmes (CSI, NCIS etc) look - and sound even in just 2.0 stereo through the AV amplifiers and speakers - pretty good.
Sit as close as you like - regardless of how many times our mothers told us, none of us have square eyes
But maybe having four eyes helps??? 
It is usually a case of about 1.5-2 times the screen width is the ideal distance, but higher quality screens and high definition allows you to sit a little closer. As an example, I sit 9 feet away from a 7ft wide screen - sort of against the rules, but it looks fine.
And I should have mentioned in my original posting a slight query also refererring to box 1 on page 78.The text mentions that you shouldn't have to look up by more than 15 degrees. I imagine that the 15-degree indication refers to the angle that a line drawn from the (middle of the ? top of the ?) screen to the observer's eye makes to the horizontal. However, the diagram provided puzzles rather than clarifies, because the lower dotted lines in the diagram are clearly below the horizontal. Can someone from What Hi-Fi explain, please?
1. No arguing with the distances quoted as THX are the experts and have vastly superior knowledge to myself when it comes to this so they must be treated as the ideal distances.
2. This is the problem Son_of_SJ...as you point out there is a real problem with practicality here. In most everyday rooms the distances quoted are very difficult to stick to, for example, in my front room I sit about 8 feet away from my Sony 46HX853 tv which if you follow the guidlines is about 1-2 feet away from the ideal viewing distance but the problem with this is that my sofa is as close as I can practically get it to the screen already as I have a reclining sofa with a coffee table in front of it so it's just not possible to get the sofa any closer. The other issue is that the sofa is already in a strange position visually but then the seating position has been worked around getting a good position for my surround system but to place it any nearer the screen would throw out the angles for my 5.1.
My point is that those distances should be used as a guidline and you should try to get as close as you can but unless you have a dedicated room for movie viewing then it just won't be possible to stick to these distances as things like furniture and furnishings have a habit of getting in the way no matter what you try. That's just my opinion though and I'm sure some people on here would rather sacrifice the furniture in favour of the ideal seating position.
Sony KDL46HX853, Yamaha RX-A2020, Dali Zensor 5 5.1, Panasonic DMP-BDT500MR, WD TV Live, Marantz CD6003, Marantz PM6004, Beresford TC-7220 MKII, PS3, Xbox 360, QED Silver Anniversary XT speaker cable, Wireworld Chroma 7 HDMIs, Chord Crimson Sub and RCA, Chord Superscreen Mains Cable