I've browsed this thread but I couldn't determine a common judgment on viewing angles.
televisioninfo's Review is appalling in this respect
"The viewing angle of the Sony Bravia KDL-55HX820 was strikingly poor, falling below 50% of its maximum contrast when only 8˚ off-center. With a total viewing angle of 17˚, you will need to position yourself right in front of the TV for the best results. Although the contrast falls dramatically, the color remains relatively true."
but what really puzzles me is that their own First Impression Review (written by another author) drew a completely different picture!
"We were able to walk out to about 50° or 60° before we noticed a significant drop in the contrast ratio. The picture held up pretty well after that point, though: even though it wasn’t great, even at almost 180° we could still see a picture with passable contrast."
Well, after having seen a KDL-46HX820 in a shop, side by side with other TV sets, I agree with any single word of First Impression above quoted: I've found a very good angle until 60° and an very acceptable quality even beyond that. Visibly much better than the nearby EX series TVs, too.
BTW, all TV sets I saw were displaying, at the same time, the same HD source, a movie with many dark scenes and with a lot of contrast.
So, I tend to believe First Impression and (even more!) my eyes much more than televisioninfo full Review, even if supported by instrumental measurement.
However, I'd like to hear more owners' opinions about this.