How much does this affect the PQ? and are most lcd's have this effect?

Most LCDs do NOT experience this.

Not sure if my samsung has it. Do I need to worry if I don't get bothered by it? It seems it doesn't affect the PQ.

http://www.avsforum.com/avs-vb/showthread.php?t=835853&page=2&pp=30

http://www.avsforum.com/avs-vb/showthread.php?t=809562

http://www.avsforum.com/avs-vb/showthread.php?t=748779

Those threads cover Sony, Samsung and Sharp. These guys dominate the LCD industry and if you read through those threads you will see clouding is a very real issue.

Heres a pic from a guy who went through 4 screens : http://www.avsforum.com/avs-vb/showthread.php?p=10325858&&#post10325858

Clouding is a issue on only a subset of Sony and Samsung sets, not all models are identified. Sony and Samsung share the same panels. The Sharp thread has only 90 posts and 14 different posters - The number of different posters is too small to be considered significant. If you review the other threads you would see that many have made several posts. You will also discover that many posts are from folks who did not notice any problems or only noticed once someone pointed it out. Only a small subset of users ever post in any forum.

Volume of posts does not mean much as some people post many times and many posts are from people asking questions.

We all notice different elements and we all have our own likes and dislikes. We each have different requirements. The key is to not worry about different technologies - find a set that meets YOUR needs and one that YOU like.

BTW the top five LCD manufacturers for 2006 - in order:
Samsung, Phillips, Sony, Sharp, LG.

21.5 percent of the market went to "value brands" http://www.digitaltvdesignline.com/news/197005667

Maybe I'm trying to look for something that is not there, the PQ is great.

Put up a black screen and turn down the lights in the room. Does black look fairly uniform on the screen? If so, you do not have "clouds" (I hate that term, it is non-uniformity in LCD-lingo). If you see it in a dark room but not when the lights are back on, it should be acceptable. If you see it with the lights on, send the set home!!!

Did the test and I think I'm okay, thanks.

My Samsung has mild clouding that can be noticed on a full black screen. If I'm thinking about technology, I can see it, usually on a fully black screen with no content, but sometimes even with content (usually at night with a zoom-through-outer-space type scene.)

But if I'm not thinking about technology, if I'm instead engaged in the content, do I think about it? Nope, I'm happy as a clam and often still stunned by the quality of an HD scene and think I'm looking through a window at something real.

Hope you continue to enjoy your set,
pixelswim

I know what you mean. The PQ of this tv is so great, just like you say, just watch and enjoy. There's always a flaw in the newer technology. Although we get consume to try find the perfect set, it's understandable because of the cost.