TLDR: Samsung/BestBuy replaced my JS8500 with a new Q90R.
I created an account just to post this. I have been following this thread for years, as a JS8500 owner, and have used many of the posts here for advice in my negotiations. I purchased my TV in May of 2015 from BestBuy. I did not purchase an extended warranty. Within the first few months of owning my JS8500, I noticed an issue with light bleed from several of the corners. It took several months, but Samsung finally agreed to a repair and ended up replacing the panel. About a year ago, some guests of ours noticed another issue where the edges of the screen were noticeably brighter than the center. It didn't bother me at the time, but over the last few months, it had gotten progressively worse; so much so that I decided to do some research on the issue.
My TV apparently had significant edge burn, so I figured I would contact Samsung to see if they would cover the repair. Their initial response was that it was out of warranty (which it was), but after explaining that they put the defective panel in the TV when they "fixed" it in 2016, they agreed to pay for the parts. I told them I wasn't satisfied with that, so they offered to cover the parts and labor as a one-time allowance.
The repair tech called and ordered the panel, then called a few days later to let me know that the parts were unavailable and it would be transferred to exchange. I called Samsung and was told that I would either be given a credit for the current value of the TV, or it would be exchanged for an equivalent model (8-series). I was told that the "exchange team" would call me within 24-48 hours to discuss my options. I was planning on arguing for a Q90R on the basis that my JS8500 had a one connect, 3D, a center stand, and a flatter back panel than the Q80R.
Two days later, I still hadn't heard back from Samsung, so I called them again and was told this time that their records showed I had agreed to an even exchange for a refurbished JS8500. Explaining that I never got a call back and didn't want someone else's broken TV, I was promised I would get a call within 24 hours. The next day, I called again, only to be told to wait another 24 hours. While waiting another day, I received an email from BestBuy informing me that my exchange had been approved. Keep in mind, at this point, I had yet to get a call from Samsung to discuss options. I ended up calling my local BestBuy and eventually spoke with a manager who told me I would be exchanging for a Q80R. I asked about the Q90R, since it is the only model with a one connect box, flat back, and center stand, and he said they could probably work out a deal to split the difference. He told me to bring my TV by the store in the morning and they would work it out.
I did exactly that. When I got there, I met with a manager who was trying to figure out what the exchange Samsung approved would be. The documents they sent did not indicate a model for the exchange, so they called Samsung. Samsung told them to have me call and ask for the exchange team, which I did. I spent another 45 minutes on the phone with Samsung while in the BestBuy store, only to be left with another promise of receiving a call in 24 hours. After spending 2-1/2 hours at BestBuy, trying to wade through all of the confusion, the manager decided to check to see how much the difference was between the Q90R and my return. The Q90R is currently on sale for $2,800 in my area, and I paid $3,000 for the JS8500. In the end, I walked out of the store with a new Q90R and a $220 credit on my BestBuy card. I think he just felt sorry for me and pushed it through.
It took a week of almost daily calls, and hours of time on the phone, but I am completely satisfied with the service I received from BestBuy. Can't say enough good things about them!