Update: Glad I went with the 65" model. It has been 2 months and the LG TV is stunning. I enjoy it every evening.
I was apprehensive with going for a 65 instead of 55 but in the end it looks terrific and not at all too big for the 12 foot viewing distance. Just right!
The 4k UHD material is stunning to say the least but even Bluray movies through the Oppo 4K UHD BDP are incredible. Even Comcast cable feed in HD is very, very good.