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Question: Concerns about Sony KDL-40v5100

I purchased the Sony KDL 40v5100 as a Christmas Gift. After reading many reviews I feel like I may have made a mistake. For the people that own and have used the TV, is this TV worth keeping or should I return the TV and get another brand? In the reviews that I read people mentioned that they had sound issues, the TV was too dark. Is this true. They also said that you may have to contact Sony to get an update?? This sounds like too many problems for a new TV that isn't even out of the box yet. Any suggestions would be helpful