The iPad 4 has a better GPU in terms of power (it uses a SGX554MP4, though the resolution means it has to compensate with a more powerful GPU to get similar performance to say, the iPhone 5), but the other devices use a different model of the SGX543- the Vita has the + model with four cores, while the iPad 3 has the non+ three core version and so does the iPhone 5. iPad mini/2 and similar devices (iPhone 4S, iPod touch 5) use the non+ two core version.
I think part of the problem with Vita games graphics is that a lot of the big budget Vita games aren't using graphical engines developed for the Vita- a lot of devs just port over their PS3/360 engines over and make games with that. Another issue is that Sony is limiting the Vita's power- it's under clocked (like the PSP was for the first few years of it's life) likely in order to make the battery life longer, and to prevent overheating. They will probably allow developers to utilize more power in the next few years, and release new Vita models that will probably resolve battery life and heat issues- that's what they did with the PSP (though it meant that the PSP-1000 didn't perform as well, especially because Sony also doubled the RAM in the models that followed it, which also limited new features to the new PSPs only).
Games like PlayStation All-Stars look really nice on the Vita- it has good graphical effects, runs native resolution, and runs at a smooth 60 frames. The engine it runs on was actually developed by the developers handling the Vita version of the game. If more games were built on engines built for the Vita, games would probably look and perform a lot better.
As for NFS:MW looking better on iOS/ Android, I don't think it's as straight as that. If the Vita version of MW ran native resolution (but was graphically the same otherwise), I think a lot of people would think the opposite. MW on smart phones looks pretty good, but it doesn't have as many graphical effects- there's no real time shadowing or lighting as far as I can tell, cars have reflections but don't actually reflect scenery, there doesn't look to be any grime or filth, etc. in addition to not being openworld and having even less traffic than the Vita version. The car models on the Vita version look really good, and are the same models used in the home console versions. Running sub-native resolution really mars up the graphical fidelity of many Vita games. If a game is going to run sub-native, it should do it how LittleBigPlanet does- LBP has really good filtering which makes it hard to tell, while still looking really good.
Last edited by tygamr; 11-03-2012 at 08:52 PM..