I have found there to be a pretty sizable bias against lg on this forum. There are a few users that seem to have a bad experience with them. I however am not amongst those and i have no problem recommending lg.
You will also find a lot of love for Samsung on this board, but, just from reading your post, I dont think you would be amongst those giving Samsung love. As far as 4k goes, I personally dont have any experience with it but most published stuff i read says you don't notice a difference until you go over 55". So at 65" you should be good. Being am early adapter however you are still going to find a lack of content for a while... if that doesn't bother you then go for it.