It depends on what you expect.
I think a lot of gamers that used to have TN screens have been trying out the XB270HU as their first IPS screen. I certainly have. Normally people who care about colors, and buy IPS screens, care about general photo-quality colors. Gamers care less about that, they care about colors in games.
The XB270HU has very nice colors. But not the dark colors. If you are a gamer who plays a lot of single-player games, where you often have to sneak through dark levels and dark dungeons, or horror-games that play in the dark, general colors will be relatively less important. And what you want is nice dark colors and black-levels. And I think that is the weak spot of IPS-panels in general. And this XB270HU specifically.
I've tried 2 XB270HUs. They both had terrible ips-glow/backlight bleeding in the right bottom corner. I've seen many (and I mean *MANY*) photos of people taking a picture of their XB270HUs with a black screen. The yellow glow is often terrible. I know photos can exaggerate. Therefor people take movies with their phones, and then take a screencap from the movie. Supposedly that shows a more realistic picture. But even then, the yellow glow can be terrible.
My first monitor had no dead pixels. My 2nd one had 2 dead pixels. And dirt in the panel (or underneath the anti-glare coating). I'm reading threads about the XB270HU on several forums every day. And there are constantly people with dead pixels and people who are disappointed because of the glow. I don't think problems are gone after the first shipment in March.
I'm convinced now that IPS-monitors are not for me. Because of that glow that breaks dark pictures. People have told me that all IPS-monitors have it. I now might buy a TN-screen after all. I still want a 144Hz G-Sync screen. Or I am waiting for a VA panel with G-Sync. I was considering the Eizo FG2421 (a 120Hz VA monitor), but it has no G-Sync. And it is only 23.5".
Lucky for me, last week Acer announced the first VA-monitor with G-Sync !
It's a 21:9, 35 inch, 144Hz cruved monitor.
VA-panel. Resolution 2560x1080.
With G-Sync. (Nobody knows about ULMB yet).
Called Acer Predator Z35.
Some people might get upset about the low resolution. Especially on a 35" monitor. But pixel density of a 34" 21:9 is exactly the same as a 27" 16:9. I play on a 16:9 1920x1080 monitor now. Yes, some stuff looks nice on 1440p. But 1080p is acceptable to me. I prefer it for the desktop and in my browser (no problems with crappy fonts). And the lower resolution allows me to configure more eyecandy. Like SSAO and better shadows, further view-distance and denser foilage. So I don't mind that the Z35 is only 2560x1080. But it might not be the monitor for everyone.