Late reply, but I wanted to add a few things in case others comes to this thread for the same reason.
1) Playstation 4 supports HDR, you don't need the PRO for this. This is also true for ATMOS when you're watching movies.
2) While the 4K Checkerboarding that the PS4PRO uses is good, it certainly isn't great. However, this is subjective to my taste. And my oppinion is formed from games in which you can switch between 4k mode and 1080p. In those games I havent noticed a difference worth the price. Sure, things are sharper and so forth, but I wouldn't recommend buying the console just for that.
However:
3) The best thing about the PS4 PRO is enhanced FPS-modes which makes games run with increased frame rate, as well as the Boost Mode in settings that makes older (non pro-patched) games run better. You can except less stutter, smoother movements and so forth. This is especially true for gems like Bloodborne.
4) Games runs, and loads faster with the PRO in general. It also enhances PSVR games, which might make the PRO worth it if you're interested in virtual reality.
For reference I'm using my PRO with a LG Oled B6V television. While my best friend has an original PS4 and the same TV, I've never had a situation where he has noticed a big enough difference to make him want to buy one - despite playing almost all the time.
You can check a couple of Youtube-videos in 2160P to see if you notice a difference in resolution, while not the best in bitrate, they should still give you a better look at what the PRO can deliever.
Links:
4K UHD | Horizon Zero Dawn – PS4 vs. PS4 Pro 4K Mode Graphics Comparison -