Hi all, I want to buy a iMac for myself as a kind of Christmas present. 
I've already possessed a 2012 13" MBA, and I absolutely love it. However even though 1440*900 on a 13" is actually bigger than I expected, I still find it lacking in real estate when I'm reading PDF, doing essays, and dealing with other applications in the same time. Not to mention the HD 4000 is a bit lacking at 3D gaming (even though I've beaten XCOM: Enemy Unknown with it).
I want an iMac now because the huge screen size should give me plenty of real estate to work with, and I like the concept of all-in-one because then I don't need to mess with cables and stuff, and moving it around will be easier when I finish my master program next year.
My current problem is the size and the specs. First I'm not sure how big the difference is of the 21.5 vs 27 in everyday usage. I've used a DELL U2311h for a few of years so I know what's an 1920*1080 resolution like (though I really hope the iMac glossy display can bring out better display quality, I'm not fond of U2311h's matte display). However I've never used a 27" before and even never seen a 2560*1440 resolution in action. One side consideration of mine was if I'm playing games on 1920*1080 on the 27 inch, if the graphic quality will look blurry because of not using native resolution (why not run native 2560*1440 you ask? Well because afaik the GPU won't handle 2560*1440 really well unless I'm using 680MX - which sadly may become out of my budget).
Finally, because the specs between the 21" and 27" and even the low and high spec of them is very different (and even silly, regarding the 5400 rpm HDD), I'm having a hard time to choose them. I would go high-spec 27"(sans the 680MX) which seems to be the best spec with least trouble wise, but I'm worried that the user experience out of it is not that much better compared to using a 21" top spec.
So what's your suggestions guys? I've already done a lot of research before, but I'd like to hear more about it.
I've already possessed a 2012 13" MBA, and I absolutely love it. However even though 1440*900 on a 13" is actually bigger than I expected, I still find it lacking in real estate when I'm reading PDF, doing essays, and dealing with other applications in the same time. Not to mention the HD 4000 is a bit lacking at 3D gaming (even though I've beaten XCOM: Enemy Unknown with it).
I want an iMac now because the huge screen size should give me plenty of real estate to work with, and I like the concept of all-in-one because then I don't need to mess with cables and stuff, and moving it around will be easier when I finish my master program next year.
My current problem is the size and the specs. First I'm not sure how big the difference is of the 21.5 vs 27 in everyday usage. I've used a DELL U2311h for a few of years so I know what's an 1920*1080 resolution like (though I really hope the iMac glossy display can bring out better display quality, I'm not fond of U2311h's matte display). However I've never used a 27" before and even never seen a 2560*1440 resolution in action. One side consideration of mine was if I'm playing games on 1920*1080 on the 27 inch, if the graphic quality will look blurry because of not using native resolution (why not run native 2560*1440 you ask? Well because afaik the GPU won't handle 2560*1440 really well unless I'm using 680MX - which sadly may become out of my budget).
Finally, because the specs between the 21" and 27" and even the low and high spec of them is very different (and even silly, regarding the 5400 rpm HDD), I'm having a hard time to choose them. I would go high-spec 27"(sans the 680MX) which seems to be the best spec with least trouble wise, but I'm worried that the user experience out of it is not that much better compared to using a 21" top spec.
So what's your suggestions guys? I've already done a lot of research before, but I'd like to hear more about it.