Those Dells do look nice, and the price for a 23" isn't bad at all. I am contemplating a 27" at 2560x1600 ,but its a lot of money. I'm figuring 2560x1600 has to look extremely nice,but for gaming? I have a GTX 680 and I know its overkill for a single monitor at 1080/1200 but never lagging is also extremely awesome.
I do have a 32" 720 samsung TV that I use as second monitor for my Internet browsing and for extra room, so the 27" would really be overkill.