27'' 1440p ips monitor needed

So, after seeing games on a 1440p ips screen I have to say screw my 7+ year old TN monitor, there is no going back!.

The thing is, I am looking for something with very little input lag and reonaction time. I know everyone is going to recommend me the korean monitors, but it would be a real pain to get those shipped over here. So, what are some recommendations? The 2 monitors I found so far:

the Viewsonic VP2770-LED; with a total input lag of 12.4 ms but a total response time of 18.6 ms (half of that with activated overdrive)

or the Asus PB278Q; input lag of 22.5 ms but it has a reaction time of 11.2 ms (again getting halfed with the overdrive function)

 

So, would I feel any difference between 12.4 and 22.5 ms of input lag? I'm pretty sensitive to it (can't play with vsync at all, I also have an lcd TV hooked up to my PC and even in "PC mode" it would be totally unplayable on that thing) Or should I favor the lower reaction time? Both monitors were pretty equal in regards to picture quality. 

Also, what settings should I turn down if I ever encounter a VRAM bottleneck? I still have a 2GB GPU, so I guess it is possible. I heard AA is not needed on high pixel density monitors anyway, but will that safe a lot of VRAM?

Or are there any other 1440p monitors out there that are usable for gaming? Thanks in advance.

I can personally recommend the ASUS PB278Q. I feel like there are no drawbacks with this monitor. I don't notice much when I play fast paced games, and I do really well in FPS. ASUS have worked some magic with this monitor. Unbelieveable. It seems like ghosting and lag is much more noticeable on other 1440p monitors. But this panel is so appropriate for gaming. Worth every penny.

2GB is fine for 1440p. 3GB is kind of the sweet spot. A single high-end card like a GTX 770 or a 7950 and upwards of that should be able to play games on ultra settings. Lesser cards will require you to turn down the settings.

I have a 770, so that should be no problem. After reading some reviews though, it seems that the viewsonic I mentioned is better in regards to input lag and ghosting than the ASUS PB278Q while having the same image quality. It cost 100 bucks more than the ASUS a few months ago, but now they're both 500 € here. Does anyone have experience with viewsonic monitors perhaps?

http://wecravegamestoo.com/forums/monitor-reviews-discussion/13392-viewsonic-vp2770-review-2560x1440-semi-glossy-pls.html

Yeah, you'll be fine either way. And the 770 will handle that amount of pixels. I just know that ASUS make a quality product.

So, does anyone have experience with the viewsonic VP 2770? From the reviews it seemed like it had the least input lag and that the response time is actually half of what it gets marketed at. So, about 6ms response time for such a monitor should be okay, I guess? I'm currently using a pretty old 5 ms TN monitor, I just don't want a lot more ghosting than what I am used to tbh.

Okay, I risked it and went for the Viewsonic VP 2770. Took it out of the box, plugged it in and HOLY CRAP! The picture quality is amazing. No dead pixels (couldn't find them on a completely black/white image) and backlight bleed is tolerable. Couldn't feel any input lag when moving the cursor as well. Then I started up a game and was completely disappointed. Input lag was horrible, the game nearly unplayable. Turns out I just had to set maximum prerendered frames to 1 instead of 2 though (that dropped the framerate a bit, but i'd rather have lower fps than input lag). Input lag gone, amazing image quality and very little ghosting. I'm absolutely happy with it, and I can recommend it if someone is also interested in one. Also, a gtx 770 with 2 GB or VRAM is totally fine for gaming in 1440p (just turned AA off, don't really need it anyway at this resolution) and I'm fine. Even BF4 runs flawlessly.