IMac :: How Good Is The 5750 In A I7

I have read a few posts of new i7 users posting various stats on their machine. I am specificaly interested in the gpu performence (without OC). I am a traditional tower pc guy, but i have slowly but surely been able to convince myself of the relative merits of going loaded imac i7 over low end MP (the least of which is the horrible value and waiting 500+ days for no real improvments other than having the base now include a few bto upgrades to save you a few hundred bucks...but dont get me started).

Anyway, back on message, NAS solves my concerns about extra HD's, the cpu is certanly fast enough, mem not an issue...so my only concern is gpu.

Just looking at it from a price perspective, i am not sure how comfortable i am that a $130 graphics card will keep me fat and happy for 3 years (tech refresh assumption). I don't need a $600 cards, but when i have typicaly built pc's, the last few years, a $300 or so card has kept me happy. With the imac, it appears that switching gpu's is not easy or something i will probably do during its warranty covered life cycle....

So how good is the card (sorry it took so long to get there). I am a somewhat power home user...not professional, but i probably fall under the label i saw floaing around on another post as someone using 500 bucks of sw to load up raw images of their cat...or in this case kids and a golden retriever. I love games, but to be fair, my xbox has replaced most of my need for quick fps. 27in is a big screen. Can i play most games at full frame/speed extra? I assume photo shop cs5, et will work fine.

i really am on the fence on which one to get, i guess next week hopefully i can really price compare them, but the MP just seems to be such a god awefull value that its hard for me to jusitfy buying the low end model...my legacy prejudiceness against all in ones is taking a bit to get over...the imac seems to be the obvious choice.