Just last week I took advantage of the same promo and purchased the PS4 Pro. I only have a 1080p tv so thus far I haven't noticed anything that stands out as being improved. My purchase was based on a few things:
- one this might be the best deal I am able to get on the Pro. Perhaps there will be something better during black Friday but with the promo and additional trade in items (a PS3 is didn't use, an extra PS4 controller, and some games) I only ended up paying about $120 for the upgrade.
- Even without a 4kTV it is reassuring to know that I will be playing the best possible version of games going forward whether it is better frame rate, slightly crisper images, or more (depending on patches). For example, when the Last Guardian came out I read about how inconsistent the frame rate was for standard PS4's but it was much better on the Pro. I like that I won't have to worry about those possible issues going forward.
- Lastly, eventually I do plan on getting a 4K tv when I find the right deal. I could have held off until then but it's nice to know that once I do upgrade my tv I'll be all set when it comes to gaming.
My only complaint is that it doesn't have a 4K Blu Ray drive but I'm not too upset about it because it gives me an excuse to NOT feel than need to upgrade my Blu Ray library, which has grown rather large of the years.
If your 4K has true HDR I think the Pro is a no brainer. From everything I hear HDR is a difference maker.
Also this website has a comprehensive list of games with Pro patches and how the patch helps, or in some cases doesn't help. It also has a list of games without the Pro patch that benefit from the Boost mode to improve frame rates.
http://m.neogaf.com/showthread.php?t=1324251