This tv seems to have mostly the best of both LCD/LED and plasma technology. The images look great in either a dark room or bright room. And even though an LCD/LED may have a slightly brighter screen in a bright room it won't be noticeably brighter, as well it beats any tv in a completely dark room given its perfect blacks which are achieved since the diodes can completely shut off. Though when there isn't enough contrast, at average pixel luminance, there may be some unusual vertical artifacts that cause the center of the screen to create cloudy grey bands instead of a pure black. So when viewing a very dark movie there might be large vertical strips as the black levels are constantly shifting on the screen. This doesn't occur on a good plasma TV. One other negative is that the LG OLED has some judder with fast pans so it doesn't handle movement as well as a plasma (from 600Hz up to 3000Hz for a Panasonic ZT60). This is because even though the OLED pixels respond faster than on a plasma TV the OLED TV's display uses sample-and-hold technology which results in worse motion clarity compared to the plasma TV. This OLED tv has a refresh rate of 240Hz so it is closer to an LED or LCD tv in this regard. The judder can be adjusted using the motion smoother in the menu, but then one gets a video camera effect (soap opera effect). The OLED also has excellent off angle viewing with no noticeable loss of contrast or colour, and excellent image uniformity, much like a plasma tv.This tv is 1080p, and 4K would normally be useless on this size of tv except it would evidently resolve the problem of artifacts (horizontal jaggies on object edges) that are seen on this tv's 720p passive 3D, whereas the active 3D technology gives one a full 1080p resolution (the trade off with active 3D being that there is more ghosting prevalent). But if 3D is not an issue for someone and one is already use to LCD/LED refresh rates (compared to plasma) then this tv is likely the best tv to buy other than the 4K OLED. This TV looks stunning given its thin bezel, curved screen, and slim elegant pedestal. Overall it appears to be the best tv on the market now other than LG's 4K OLED TVs. The Panasonic ZT 60 was the best TV in 2013 (and some still argue it has a better overall image than the OLED for colour and detail in shadows, not to mention the way it handles motion, if not black levels) and who knows what the best TV will be next year. Some people will hold out because of the price, and others because of the motion issues compared to what they are use to on their plasma TVs, and others because of the lack of 1080p 3D on this TV, or others just because it isn't enough of a jump in quality over their present TV to make it worthwhile. All in all this is a stunning TV which likely represents the future direction in TV. I remember the first OLED I saw back around 2007 which was a tiny (about 10x7") Sony selling for about $6000. LG has come a long way in the designing of their TVs too. I remember shunning their TVs simply because of their rather clunky frames, and heavy handed use of logos on their TVs. This TV though is elegantly designed and looks like maybe it's as close to a piece of art as a TV can be.
There are other advancements on the horizon: LG currently has a prototype for an OLED HDR (high dynamic range) TV which is 60% brighter than the current OLED TVs, though the Samsung LED JS9500 would still be about 25% brighter than the HDR OLED. (Update Sept.2015: The flat 4K OLED LG55EF9500, coming out in September 2015, will have the HDR feature.)
April 14,2015: Interestingly today I was able to see this TV surrounded by a selection of LCD/LED and plasma TVs in a showroom, and remarkably, and initially, there was very little obvious difference between any of the TVs. I had thought originally that it would blow away any TV side by side. Though when all of the screens went white it was obvious that the LCD/LED tvs had the brightest whites, and the plasma the dimmest, with the OLED in between but leaning towards the diminished brightness of the plasma. The biggest difference though moving back and forth in the room was to see that the OLED colours and tones looking so much better than the LCD/LEDs no matter where one stood in the room, though appearing similar to the plasma's excellent uniformity. In this environment with bright lights, but no windows, the blacks on the OLED were black but not overtly better than the other TVs. This TV shines though over the plasma in bright rooms with natural light streaming into a room where plasmas lose their contrast and colour and go greyish, and over LCD/LEDs and plasmas in a totally black room where this TV will have perfect blacks compared to the dark grey light of the plasma and the much brighter darks on LCD/LEDs. So yes, this is the best TV yet, but in some environments it won't look that much better over all. This TV is the most versatile TV given its excellent image quality in any lighting situation.
November 2015: The 9300 series is being discontinued and replaced by the EG9100. There are no big differences that I know of other than the different base and a Web OS, version 2.0. For those interested in the 3D evidently the flat screen 4K EF9500 model is the best 3D TV ever, though the 3D on the curved 4K EG9600 is for some reason more finicky (see CNET) as ghosting can appear, much as it tends to on active 3D TVs.
I purchased an LG 55EC9300 based on the positive reviews and online research.
Unfortunately, television was not working within two days of purchase. Am now involved in a nightmare of a process trying to set up a service appointment with LG.
I regret my purchase completely. LG Customer Service is continuing to fail miserably. Were it not for the practical difficulties of transporting the television from its current location, I would have returned it already.
If I could give my television a 0/5 star rating, I would. Alas, half one star it is.