not quite sure whats the differences are exactly between ahva and ah-ips, but looking at the review the gsync 144hz 1440p ahva ips monitor performs well in terms of

1. refresh latency 5.5ms (ahva ips) vs 1ms (tn panels)
2. no overshot. basically the overdrive results on average settings was excellent.
3. input latency is class 1 which is perfect for gaming. even with gsync enabled the latency didn't increase by much to affect this.

overall seems the Acer XB270HU 27-in 1440P 144Hz IPS G-Sync is the monitor of the year

there is an asus ips ahva monitor same size specs but is using freesync. but according to the reviews, the freesync doesn't perform as well as g-sync when comparing those 2 particular monitors anyway when it came to high and low vrr window. e.g. was capped at 90hz, whereas the acer was at 144hz. and the asus though minimum is 35 which is lower than the other freesync monitors i've seen, it still doesn't beat gsync method for handling when fps dips that low even to as low as 1fps. freesync just doesn't handle under vrr window as well as gsync unfortunately.

but there is the 100-200 usd price difference usually between a freesync and gsync monitor .... thats a lot of money .... but then again your also bound depending on whether you decide to get an ati or nvidia gpu ...... it's unfortunate that nvidia in particular created this intentional lockdown on consumers being able to choose between gsync and freesync monitors without being locked out due to gpu brand choice ....

that said i'm waiting for pascal and getting that.

actually i thought that for vrr window under, the freesync can go much lower. just that the manufacturers for the monitors have not done so.

i also heard there seems to be some issue with the scalars used on freesync monitors. think it had something to do with how it manages situations when under the minimum window.

the gsync solution they churn out repeat frames to handle the situation, and can handle even up to 1fps situations.

by the way any idea how much is the XB270HU after gst included ?

just to clarify, say the lcd manufacturer added a 9hz minimum refresh rate. does that mean the minimum vrr window is now 9fps ? so there won't any any issues unless you hit 9fps ?

whereas nvidia's is 30fps minimum, but their solution is also able to properly handle below their minimum vrr window by doubling/tripling frame rates all the way down to 1fps.

Or is some of this a misunderstanding on my part    not expert here hehe....

ooo..... so no wonder nvidia used their method to deal with it .....

by the way i notice most of the manufacturers for freesync are using minimum 40hz. only the asus i notice was 35hz.

gsync on the otherhand are 30hz (not sure if most are but some definitely are).
only thing freesync i see can do now i copy what nvidia did with the frame doubling/tripling using cache ?

but from what i read even if they did the same, they would not be able to fully copy nvidia. but i think that was related to overdrive. nvidia took it into their own hands to handle overdrive, whereas ati left it to the vendors.

judging by the results seems it was worth nvidia doing the overdrive. though it's a shame you can't get ulmb to work with gsync at the same time 
PS: newer gsync monitors like the acer ironed out most of the nasty cons related to gsync. There is still 1 weird issue, but according to pcpers it isn't something that you would usually notice especially in gaming. Something about colors going bonkers in certain situations :/

freesync on otherhand, only main issue i see is how they handle the minimum vrr window and below it. also noticed that for asus to get 35hz minimum they had to cap the max vrr window to 90 instead of 120. i don't particularly liked that solution because the gsync acer monitor can do 30-144hz (exception is when enabling ulmb you need to cap at 120 i think)

Gsync 4k @ 144hz i am down with that

1440p no thanks hahahaha as i already got 1440p

Guys, is this 2340L  & 2415H differ in ips type?some source said both uses AH-ips ...  does it differs very much from e-ips in u2312?  Im thinking of these two. Budget 600-700
Which one better?  Ah-ips or e-ips?  Enlighten me pls on these ips type...

S series afaik uses VA panel instead of IPS, but i could be wrong. newer models might have changed

in short, AH-IPS > E-IPS. thats all

thanks for reply.. going from TN+matte to IPS+glossy really an improvement..

just bought the S2340L..
satisfied with it. 

though, the reflection of glossy screen can be annoying when playing competitive game like cs:go

i have a question, if the lcd have dust/debris in between, can i claim the warranty?

its samsung 27 sd390, im sure its a debris/dust as before it only sit at the bottom of the lcd, after i move it into the box(moving away) it move to the middle of the screen..

i try to ketuk2 but it only move very slow and i afraid will damage the panel..