Hi Viper & Test,
Its such a tough call as to whether to swap ,as the risk of getting something worse is there.I'm not sure what the cause of your problem is,but its down to what you notice when watching films/tv etc.
I had really bad clouding and flashlighting on my first 650 panel,and it was noticable in normal viewing (dark films like Blade Runner,The Crow etc ),so it was a fairly easy decision to have a replacement panel fitted under warranty.
I thought about living with it,but I just couldn't,my eyes were drawn to the clouds every time a dark scene came on.
I had some luck in getting an "almost" problem free panel,no clouds visible at anything but high backlights,and very minor flashlighting from one corner.
I dont think theres many "perfect" larger size LCD screens about,almost all exibit some form of problem that people like us notice ,and get annoyed by.
Basically,if it was me,and I kept seeing the imperfection,I would have it replaced.
It's a horrible position to be in though,very frustrating to have these sort of issues when you have laid out this much cash.