Mindaugasinas

I would ALWAYS choose a 27" 1080p panel over a 24".  Here's why.
The main gaming 24" panels all use the same AU Optronics panel: the M240HW01 V8.  The Asus VG248QE, the older non blur reduction  Benq XL2411T, XL2420TE, XL2420TX, and the newer benq blur reduction models XL2411Z, XL2420Z, and maybe the XL2430T (not to be confused with the older T series) use this panel.
 
This panel has an issue where the gamma point drops as the refresh rate increases, washing out the image greatly.  On these panels, Gamma 2.2 at 60 hz refresh rate drops down to a washed out 1.9 at 144 hz refresh rate.  The VG248QE does not have OSD gamma adjustments, but the Benq monitors (starting with the newer revision of the pre blur reduction T series, and the blur reduction type Z series) have an OSD gamma adjustment to compensate for this, somewhat.  Not sure if this also compensates for the color point changing.or not or if that still needs ICC profiles, but the gamma degrading and the color tone dropping off at higher refresh rates is an issue with choosing a 24" 1080p panel.
 
 
The Benq XL2720Z uses the M270HTN01.0 panel.. This panel DOES NOT DEGRADE IN GAMMA whatsoever when you increase the refresh rate.  2.2 gamma at 60 hz remains 2.2 gamma at 144 hz, although the gamma curve across the brightness levels does not remain flat; an icc profile can correct for this, although this remains basically the same point regardless of refresh rate.  Gamma 4 in the OSD puts the gamma closest to the 2.2 point than gamma 3.  Color also does not seem to degrade either.  This panel keeping the exact same gamma regardless of refresh rate is something all reviews completely overlooked when discussing 27" or 24" panels.  The gamma and color balance remaining spot on is a huge benefit of buying a 27" 1080p 2720Z.
 
Can't speak for other 27" 1080p panels, however.
Version 4 firmware on the 2720Z (and the other Z models) tons down the aggressive overdrive and adds a hidden blur reduction AMA setting which makes things look much better than the V2 firmware does, especially when you lower the contrast (this is required if using the new AMA setting, as inverse ghosting is removed, at the cost of normal ghosting being increased).
 
So I would choose the 27" 1080p over the 24", any day.
And I have two VG248QE's so I know how it drops gamma and loses fidelity massively.

Now thar's a boomer. My order will be delivered only on april 21st. Damn...

There is no way I could try these. I live in Lithuania, people here buy only cheap products, so no good stuff is on the shelves even in the big computer stores. Only cheap logitech and no name stuff. My order will be shipped from the Poland.

Ok I'm about to push confirm button on this order:
Corsair K95 RGB Cherry MX Brown
Corsair SABRE RGB Laser mouse
Corsair MM200 XL Gaming mouse mat (450mm x 375mm x 4mm)
Confirm or change something?

Id'e get an Optical mouse.
 
 
I have pretty much the same setup

Ok I'm about to push confirm button on this order:
Corsair K95 RGB Cherry MX Brown
Corsair SABRE RGB Laser mouse
Corsair MM200 XL Gaming mouse mat (450mm x 375mm x 4mm)
Confirm or change something?

I'm ordering now Corsair K95 brown or K70 blue. I'm coding alot with C# and do game even more. I'm in the online store page now so I need a quick reply

But isnt ati-dip coating is to thick? I imagine that its a thick coating, so it might compromyze thermal propertyes?

Ya but why do you want g-sync / 144hz? 
 
Like I said before, 1440p monitor with lower fps will visually look better. The difference extra frames above 60 makes is very little compared to resolution and screen quality. 
 
If I was in your shoes, which I used to be, I would get a non reference gtx 980 Ilike a g1 or a strix) and a quix 1440p samsung pls panel that clocks to 96 hz stable. 
 
are you a really hardcore bf4 player or something? cuz they are like the only ppl who would seriously care about getting an insanely high refresh rate, 

Can I inquire why you absolutely must have a 144Hz G-Sync monitor?
 
Either way if you have the $ I would get a 980 (I did) over the 970 if you must have such a monitor.