I’m pretty sure to notice the difference the title has to be mastered in 4K HDR start to finish or have a playback chain that supports dynamic tone mapping.

A good test would be a legacy movie like Alien or Predator in 4K vs the 1080 bluray original release.

They now master to wider brightness and color limits and this translates to a punchier picture regardless of resolution. The benefit the 820 adds may be similar to the darbee. smile The 820 expands the brightness and color of SDR to simulated HDR if you enable it. (Similar to dynamic tone mapping in highend displays.) The cheaper 450 also does this. We have a decent collection of blurays and they found new and impressive life with tone mapping to HDR and 1000nit output applied.

All the vids on youtube I have found for comparison don’t seem to understand this and poo poo 4K HDR. The vid either shoots in 4K HDR and scales down to 1080 (which looks great and close to the same on non HDR playback displays) or shoots in 1080 SDR and scales up to 4K without dynamic tone mapping and looks identical....

Hope this makes sense to others.