Games look okay on these monitors at different resolutions. It's not ideal, but Dell has generally done a good job with the scalers in their UltraSharp monitor line. A 2560x1600 monitor can provide an amazing gaming experience. Most of my games run fine at 2560x1600 with a single Radeon HD6970
Upgrading to a 4-megapixel monitor may give you a reason to want to also upgrade to a next-generation graphics card fabricated at 28nm in the next six months.
i7-4770K, H70, Gryphon Z87, 16 GiB, R9-290, SSD, 2 HD, Blu-ray, SB ZX, TJ08-E, SS-660XP², 3007WFP+2001FP, RK-9000BR, MX518