why would there be a much bigger difference if the vid was high def. I've said it before and I'll say it again, DX version, lighting, fancy effects makeup the last 10% of how it looks, the modelling and the texturing are 90% of how a game looks. Importing the same models and textures will have a fairly small effect. The difference would be in that the Cryengine can smack a hell of a lot of detail on over a very large distance and still look very very good. Its lighting and shadowing are more up to date and it does look better because of that, just not massively. Things like looking right and moving left watching over a small shaded courtyard, the differing light levels on various boxes was all pretty impressive.
But at the end of the day, as I keep saying, its all about design, models and textures which all takes time. Same can be said for physx, do you know why there is only 1 level in 2-3 games specifically made for it. NOTHING to do with the physx card, or they physics. THe levels have to be designed from the ground up to be destructable. That means every little wall has to be designed in 100 pieces rather than one, theres most of the time right there. THen you have to make the engine work well with it, cope with the extra pieces, tell the engine how to blow the wall up, and make sure that the stuff doesn't cause problems, the players have to be able to move over small bits of debree and not get caught on it, they need to not clip with other models and dissappear. Its simply 100% about more design work and time needed to do it. AS games move on better design tools, faster work in 3dsmax, better compression of textures all leads to that stuff improving and time taken to develope a level reduces, giving them more "extra" time to do more complex things with levels.