While IPS will improve your experience with photo editing, and improve the view of someone sitting next to you while gaming, if you do not have someone sitting next to you that you are concerned about having a good view, then a 120 / 144Hz TN monitor will provide the far better gaming experience. IPS do not provide more "vivid" color, especially at the low end of the price spectrum.; they are capable of providing more "accurate" color and you must be clear about that distinction.
We have six desktops here ..... one has a $1,000 Dell IPS (Son No. 2 minored in photography in "Kolludge") ...... one has a $200 $120 Hz Asus TN panel and another has a $250 Asus 144 Hz. I don't get to game much myself so before Son No.2 starts a gaming session, he'll always poke his head into my office and see if I'm at it ..... if I'm not, he'll game on the 144 Hz before he'll use his own IPS. The colors on the 120/144 are truly vivid with sharp edges..... the IPS by comparison looks washed out and "fuzzy" by comparison, not to mention the ghosting .... I don't see it as much but the 3 kids find it annoying. And it is not that noticeable until ya can go back and forth from one to the other.
Ligtboost and now G-Sync puts an end to the ghosting issue. On the other hand, what works for gaming, is a hindrance in photo editing ..... if you try and edit gramdmas glamor shots, the oft overly vivid color of the 120/144 screens will have granny looking like a madame on screen, so when you color adjust, the prints look flat.
Read more on blurbusters and tftcentral
Asus 120 Hz
Dell IPS
http://www.blurbusters.com/zero-motion-blur/lightboost-faq/
http://www.tftcentral.co.uk/reviews/asus_vg278he.htm
Don't forget that one of the key selling points of this screen is its support of higher 120Hz and 144Hz refresh rates. In practice this does make a noticeable difference and should not be overlooked. While it doesn't change the fundamental behaviour of the pixels, the smoothness of movement is vastly improved, even when simply dragging windows around a desktop or moving your mouse pointer. The increased frame rate support is also very important to high end gamers, and those who play a lot of FPS particularly. Given the support of 120Hz+ here as well, the screen can also support NVIDIA's 3D Vision for stereoscopic content. So for those who might want to play 3D games this is another big benefit.