Samsung UE55C7000 Replacement

I have had alot of problems with my Samsung UE55C7000 and i am returning it. I am now looking at replacements and am not sure what to go for but am considering a plasma instead of LED as the problems i had were with clouding and it appears to be a common issue.

I would appreciate some ideas as to what TV to go for but i am looking at the following and my budget is around £1700 and i would like a 3d tv over 50 inch and would need to be able to connect to my nas via ethernet or wifi.

Samsung PS51D8000 with 3 year warranty £1650

Panasonic P50VT20 - Prices around £1500

any help would be appreciated