If I already had a Nth generation console, I wouldn't buy a same generation, same platform premium model. I could buy one if I had no console, if the premium model weren't too expensive and it offered higher and more stable framerate and possibly higher level of FX and AA. Higher resolution could be a bonus, but it would be last in my wishlist, unless I bought a significantly larger monitor or TV than the ones I currently own, that could make higher res more desirable, but with a 22" monitor and a 32" and a 40" TV I'm already fine enough with 1080p, I should get something a lot larger to need 4k, for my tastes.
Better CPU and larger main RAM could be welcome if console games offered p2p multiplayer, and if the premium console offered non gaming functions needing it, not simply home theatre ones, but also PC replacement ones, say, video capture and editing, computer graphics, etc. But having to run on base model too, games couldn't use the extra CPU power except for what's needed to assist the upgraded GPU. They couldn't offer better AI or higher number of players and/or active items on the scene, for example.
Anyhow, only at a good price and not having a same gen, same platform console yet, a premium model could be a nice purchase, else no, not for me.
Stwike him, Centuwion. Stwike him vewy wuffly! (Pontius Pilate, "Life of Brian")
A fart without stink is like a sky without stars.
TGS, Third Grade Shooter: brand new genre invented by Kevin Butler exclusively for Natal WiiToo Kinect. PEW! PEW-PEW-PEW!