The 8500 is very good, and I've no problem recommending it. At 65in, there is far less choice than 55in, and prices are less keen. If TV A is £X, and TV B is £X plus 5%, and TV B is a rather better spec, then TV B might make sense, since your spending a fair amount anyway.
Currently, the J9000 is £3299 in a 65in, and the 8500 is £2999 (there are tradeins for both those models). The Sony x8 is £2499. And there is a tradein for that as well. I'd advise going to see if the extra is worth it. The extra £500 for the 8500 is possibly justified over the Sony x8, but its up to the individual.