Any complaints about it and if you don't mind me asking, how exactly would you OC the monitor. Is it done in the video settings in the pc or a setting on the monitor?
Overclocking is achieved via software, but very few monitors are capable of being overclocked. The process involved patching my drivers (since I have an Nvidia card) and creating a custom resolution of 2560x1440 @ 120Hz in the control panel.
My impression after a few days of ownership is that I probably would not recommend paying a premium for an overclockable monitor. Mine works at 120Hz, but when set above 90Hz it exhibits a visual defect similar to scanlines on a TV and makes a slight buzzing sound. More importantly, although I get smoother motion when moving my mouse, when moving windows it is choppy, as if frames are getting dropped. I don't know if this is an issue with the drivers, monitor, or DVI cable, but as a result, I have been running it at 60Hz exclusively.
Overclocking aside, there's really nothing negative to say about it. I ordered a Perfect Pixel version (though they may not be offering these anymore) and there are no pixel defects as promised. The picture looks beautiful in day-to-day use; I have it sitting next to an HP LP2475w that I paid $600 for a couple years back, and it looks superior to the naked eye, though I haven't had time to do calibration and get a quantitative assessment. One thing I would say for people new to this type of monitor is that the pixel pitch takes some getting used to. Everything is noticeably smaller than on the 24" 1920x1200 monitor.
The stand that comes with the Overlord is serviceable. If you don't need to adjust height/tilt, then you can get by fine with it without having to pay extra for an aftermarket stand. The bezel is fairly large (common with most of the Korean monitors too), but otherwise it is alright in the looks department.
One caveat I would mention is that I expect that if you order a monitor from Overlord in the next month or so, there is a very high chance of it having dead or stuck pixels. The guy running the company mentioned that the stock he got from his supplier was only about 30% pixel perfect rather than the 70% he was promised, so the pixel perfect models were oversold. The implication I would draw from that is that any pixel perfect screens that come in the next shipment will go towards fulfilling existing orders first rather than going into the pool of monitors that go to the people who don't pay extra for the pixel perfect guarantee.