There is yet one more compounding factor to the debate: We have gotten to a point in time where increased graphics resolutions and textures give us increased diminishing returns (ie, spending tons of memory and CPU for tiny-winy boosts) and all people ever talk about are how important those tiny boosts are, but ignore the truly groundbreaking GPU additions.
The biggest changes that we will ever see in graphics engines in the near future are post processing effects. This includes fancy lighting, reflections, smoke, particle effects, anti-aliasing, ambient occlusion, tessellation... terms that most gamers may have heard of but never knew what they were (because no single effect is a GIGANTIC change). These are the features that set apart the true 'next-gen' game engines such as CryTech's CryEngine. These effects are also at the root of modern major gaming news such as the Watch_Dogs downgrade.
CryEngine 3 can give a medium-hardware machine such a pretty picture not because it has high resolution or fps, but because every single element mentioned above was considered in the engine's design from the beginning, given the devs time to optimize rendering for them. Watch_Dogs got downgraded because the engine was designed to print a basic image to the screen at solid fps. They then put in some of these and cranked it up to 11 to see how pretty it could be at E3, only to realize months later that the engine was never designed to handle all of them at once. You can only optimize for them so much when you don't take these seriously in to account - when they aren't included in the ground floor. These features are a tiny after thought when they should be integral, and not a single one of them is a gamebreaker by itself.
The same happened with Assassin's Creed 4: it was built with the Screed 3 engine and had some pretty lights tacked on that it was never meant to handle (Screed 3 was based off of Screed 2, etc..). The result: turning god rays on in Black Flag tanks your fps. While Ubisoft is known for having terribly optimized games, this is a broader trend with most companies. Tomb Raider trumpeted TressFX for Laura's hair, but how did the game handle it? The result: turning TressFX on in TotalBiscuit's mega rig tanked his fps by over half. The new inFamous ran at 30fps but still looked better than many games that can run 60, and it was because they dedicated early development to lighting and reflection. The game had some issues, but very few people complained about the game not looking good.
CryEngine 3 is considered one of the truest "next gen" engines, and it was released FIVE YEARS AGO. Just sayin'.