Samsung has renamed their Premium UHD models and for 2020 we get the Crystal UHD naming which in all honesty feels more catchy even if their capabilities are far less capable than the Quantum Dots. The TU8500 is the highest Crystal TV you can find while it has only been announced for the UK and European markets. The first major change we find in the TU8500 is the use of Dynamic Crystal Display technology instead of Quantum Dots which means less accurate color reproduction. The TV is also less brightness capable according to the given rating.

Another downgrade we find is the use of the Crystal Processor 4K which comes with further reduced capabilities. Everything else is similar to the Q60T with the same audio system and smart functionality including Tizen and all it’s services.
Specifications

    4K UHD resolution (3,840 x 2,160)
    Dynamic Crystal Display technology
    Dual LED backlighting
    HDR
    HDR10+, HDR10 and HLG support
    Crystal Processor 4K
    2CH 20W / Adaptive Sound
    Game Enhancer, Multi-View, Ambient Mode
    3 x HDMI / 2 x USB
    ARC / eARC
    WiFi, Bluetooth v4.2
    Tizen smart platform
    OneRemote

TU8500 got dual led function, which tu8000 less.  Samsung's new Dual LED technology, which adjusts the backlight's color tone according to the content, may have improved the contrast ratio, but there's no way for us to be certain.

Better get last year 2019 model . Price  Will be cheaper.  If you don't care HDR content. Any TV should do good Job.