UPDATE 2:
As far as the image and properties of the monitor go, it is still by far the best I've ever seen.
Over the years however, the active fan for cooling the G-Sync module really pulls down the otherwise incredible monitor. The fan is uncontrolable, behaves extremely poorly and has a tendency to spin up to very loud levels when operating at the maximum advertised frequency of 240 Hz.
1) It only really seems to adjust the speed once every 10 or so minutes, or when a noticeable change in frequency occurs (like playing older games). Meaning once it spins up, the only way to shut it up is to unplug the monitor completely and plug it in again.
2) The 10 minute cycle includes when the monitor is turned off. If you turn it off while the fan is spinning loudly, the fan continues to spin for another 10 minutes even though the monitor is off. This can be extremely annoying and once again, the only solution is to unplug the monitor.
3) Even with regular cleaning/vaccuming of the fan exhaust port, the issue regularly returns.
4) The main source of heat is where the display and power cables are connected to the monitor. This is however located directly below the G-Sync module with the damn fan and it seems to be confusing the thermometers into thinking the G-Sync module needs more cooling and it revs up the fan.
5) The fan issues are more pronounced in hot months. It's usually fine, but during hot summers, you can't get around the fan other than reducing the refresh rate to reduce the heat output, which however defeats the entire point of the product.

Overall, while the monitor itself is stellar, after this experience, I can NOT recommend it anymore, nor any other monitor that has active cooling. Such an unfortunate blemish on an otherwise awesome product. I might try just jamming something into the fan or try to disable it somehow and see if the monitor can operate without it. Pretty tired of the constant unplugging/plugging to shut it up.

I have no idea HOW Lenovo thought this was fine, to kill an incredible product with a simple idiotically set up fan.... Seems like there was no QA at all when it came to long term user experience.

UPDATE:
If the fan gets loud, make sure to clean the dust from the back of the monitor where the fan is. Mine got pretty loud after a few months, I checked the back of it and the vents were completely blocked with dust. Once I went over it with a vacuum cleaner, the fan went quiet again, even on 240 Hz.

So make sure you regularly clean the dust, since the monitor has active cooling.

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Just got this thing yesterday and it's incredible. There are almost no reviews out there for this thing (literally 0 in my country), so let me share my thoughts for anyone interested.

Last few years, my daily driver was Dell S2417DG. A 24 inch, 1440p, 165 Hz TN display with G-Sync. It was good but had one major flaw, severe color banding in darker shades and horrible gamma. It was good otherwise, but when the banding happened, it was extremely visible and distracting. The overblown gamma had to be fixed by lowering it in software which caused a big amount of black crush.

As I've been on TN monitors my entire life, I was looking for an upgrade and stumbled upon the new Lenovo monitor. First the specs.

- TN (newest generation)
- 2560x1440
- 27 inch
- G-Sync Ultimate module (with a fan)

It cost me about $850 in total after a 21% discount, so pretty expensive. Had my doubts after ordering about the price but in the end, was extremely nicely surprised.

The build quality is very solid. While the Dell's plastic squeaked the moment I touched it, it is much better with the Lenovo. The stand allows wide possibilities of positioning it. You can tell it's a quality product. It also had no dead pixels or obvious defects. And not having to play the IPS lottery due to it being TN was also a huge plus.

Now, the picture quality.... I was simply blown away. I was expecting an upgrade but holy shit not this much. The colors are on IPS level and the OSD display lets you adjust to your heart's desire (it has a slew of interesting functions and you can calibrate everything there). The blacks are the best I've seen on a TN display so far. I could instantly tell the difference even when playing an old game like Tomb Raider 3. The 240 Hz is also next level in games like Unreal Tournament 2004 or any fast paced game which benefits from high frame rate. When playing something more demanding where I have no chance of reaching 240 Hz, the G-Sync makes it still incredibly smooth. I can't feel any input delay at all (a benefit of TN), no ghosting or anything of the sort. It was a little too bright out of the box, so I lowered that but otherwise, it is impeccable.

My settings:
Peak white - 155 out of 450
Contrast - 50
Dark Boost - Level 2 (to compensate for the increased gamma setting)
Relative Gamma - +0.3

If you are a fan of TN displays, you can't go wrong with this monitor. Probably the best spent $850 on a computer peripheral in my entire life.

There are also a few minor negatives:
1. The fan in the G-Sync module. It is not loud but provides a constant low ambient noise. If your PC makes any noise at all, you will not notice it but fans of absolute quiet while gaming might find this somewhat of a deterrent. A non-issue for headphone users of course but as a speaker user myself, I don't find it distracting even though my PC is pretty quiet (but not noiseless). The fan also stays on for 10 minutes after you turn off your PC before it enters deep sleep and stops with no way of controlling it through software or OSD. Maybe a firmware upgrade in the future but nothing right now.

2. The gamma shift. The one omnipresent issue of TN displays. You have to be sitting completely dead center in front of the monitor. The horizontal shift is not that bad but vertical becomes apparent even if you just sink into your chair a little. 27 is a pretty big size for a TN and I unfortunately sit pretty close to the monitor, making it slightly more pronounced. At least it will improve my sitting posture a little bit :P

3. The price obviously. As I already said, I had by doubts about shelling out almost as much money as for a new PC just for a monitor, but it was ABSOLUTELY worth it. I viewed it as future-proofing my monitor and I succeeded in that goal. I'll take high frame rate over the performance killer that is 4K any day.

4. Possible negative but not for me. The Anti-Glare coating. It is there but nothing severe, the only time you might notice it is when staring at a completely white screen. Absolutely fine in games. If you are not used to uncoated displays, you probably won't even notice.

TLDR:
Just get it if you don't mind some minor fan noise.

As soon as you pony up the dough i'll get it...sound good? ;)

(I'm just messing with ya btw....i'm happy that you found a monitor you like and are ok with. Me? I'm happy as long as there's a decent picture and sound on my pc :))

It seems like it's nice....I just like waiiting for tech to drop in price then buy if need be. :)

Thank you idbeholdME. I thought my monitor was about to blow up, until I got a vacuum on the case and its now quite again.

Buy dust filter meshes and install them on the back of your monitor. They are cheap and you can get them in various shapes and sizes as you need them.

A monitor with active cooling should have them pre-installed by the manufacturer, because dust getting into the monitor has a negative effect on performance and life expectancy. Apple had to face a class action lawsuit as they allegedly failed to install them on several of their devices.

Glad my findings helped someone. I was also surprised when it first happened to me. It seems like once a month is sufficient to keep the fan quiet. But of course, it depends on how dusty the evironment is. Generally, whenever the fan starts to noticeably ramp up, it's time for the vacuum. I don't think that's feasible, due to how it is done on the monitor (see the pic). It's not just a small box on the back of the monitor, but the module is built-in to the whole compartment on the back of it. Vacuuming it once a month takes like 2 minutes and is a quick fix. It's not like dust gets inside the actual display, just the G-Sync module. The whiter part just eventually gets clogged, which is what makes the fan go mad if you don't clean it.

I can see that there is a mesh built into the back of the module, so there is absolutely no need for another one on the outside.In that case it is as you already said: Cleaning it once or twice a month is the best solution.