I definitely feel what you are saying here. The Show is putting the Pro and Pro Mode enhancements on a lot of peoples radar for the first time, but the truth is that the Pro has been out since November and many games have offered different rendering modes for Pro owners. Some games, like Nioh and RotTR, have offered 3 different options just like The Show is doing (Nioh does it in a different way, but still three modes nonetheless). This is all new to The Show, but not new in general, if that makes sense.
It might all sound confusing on paper but when the game gets here it will make a lot more sense. There are sites dedicated to performance/technical analysis of games and hardware, like NX Gamer and Digital Foundry. Right at release, or maybe just very shortly after, we are going to have a detailed breakdown (assuming SCEA doesn't provide one of their own, beforehand) of what the true resolution is of each mode (pixel counting) and what each mode's frame rate is. The frame rate won't change display to display, nor will the internally rendered resolution of each mode (that's all within the Pro itself).
You and Blzer both said you are looking to see massive upgrades for 1080p displays, and that by itself, as you said as well, will be entirely subjective. Hopefully you both, and anyone else, will be able to see the Pro in action live, or play on one even, when The Show hits to see if what it offers is worth it for you.
If you just go off of screenshots or youtube videos, it might be hard to tell if the upgrade is "hugely noticeable" for 1080p owners. Feeling the frame rate boost, or seeing the crisper image that "enhanced visuals" down sampling will offer, are both things better experienced live, in person.
This is a good idea, and is your best bet to know for sure. Comparison videos with compression (especially youtube videos) and comparing screen shots on whatever display you have doesn't always tell the whole tale. Just playing on a Pro, or at least watching it live, will be what should really tell you if it is worth a look or not, for you.
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