A:Answer As I recall, that's a good TV!
What's Horizon? A game? The BBC series?
The Pro doesn't seem to have any new features for video playback when it comes to 1080p TVs. It is better hardware for games though. Obviously part of the benefit of the Pro is it can support higher resolutions than 1080p, but there should be real benefit for 1080p sets as well, as other than resolution, all the other performance boots will affect 1080p games too. I mean developers can potentially throw in more detail, frame rates may be better, they could run a ton more physics on it, etc. The only benefit for games you won't get is higher than 1080p in other words, but that's not the only benefit when it comes to games. (And while 4K and HDR is cool, you've got a good set-better than probably most 4K sets, so stuff should still look great!)
Personally if I were buying a new PS4, there's no way I'd buy anything but the Pro. If I already had a "regular" PS4 and a 1080p set, I wouldn't worry about upgrading immediately, though I'd probably expect to once I got a game that did something useful with the extra power. (That's just my take on it for myself of course.)