I just brought the 46Z4500 on the 19th. I really am happy with the picture, but unfortunately there is clouding at the bottom left and right. I first noticed it while watching Iron man on Blu ray, and its been bugging me. I am going to taka chance and get a replacment this week. Also noticed a green pixcel stuck on the screen. Lets hope I get a better one.
Looks like clouding is a issue with most LCD's, just depends how bad you get it. Not good thogh. Thought sony would really sort this out by now. I have seen many LCD's before getting this one and am impressed with the picture, especially SD and Blu ray HD is fantastic. Really was expecting a poor SD picture, but is definately watchable. Not sure how much a difference 200hz really is, but motionflow is impressive.
Overall , bar the clouding. Excellent TV. Oh the sound is alot better than the W4500 , but I have also got the RHT-G900 AV cabinet. So use this mainly. Great AV cabinet. Just hope I get a replacment no clouding. Oh please ..please !!