I may have missed your followup post but did the new glasses from Sony TBG-BT500A clear up the 3D crosstalk? I went from the TBG-BT400A to the TBG-BT500A (same as you) and they made no difference for me. I have the XBR-75X850C and the crosstalk has been unacceptable by any standards. There are maybe only 3 or 4 movies in my 85 3D movie collection that look halfway decent in 3D, meaning the crosstalk is tolerable.
And I'm talking about good quality-made movies, like most of the Marvel movies and Avatar for God's sake, which I'm sure most would agree are normally good quality 3D movies, right?. Well, even those movies have a lot of crosstalk on the new 75 inch 850C. The latest firmware, just released a couple days ago, didn't do a thing to fix the 3D issue and I was really hoping it would. I find myself watching my 3D content on my upstairs TV, which is Sony's 2014 55" model (850B) with passive 3D.
It's a shame I have to watch these on my 55 inch TV upstairs when I have an otherwise beautiful 75 inch TV downstairs, but they're unbearable to watch on this TV. Have two tickets open with Sony's support and they have offered no solutions so far. Keep hoping for that magic firmware fix but it never comes.