Just bought one of these to try it out. I'm coming from a full LED backlit TV (see signature). I've always been drawn to Plasma due to the 'naturalness' of the image - LCD always looks a bit hyper-real to me in terms of detail levels, and motion is compromised. I decided to take the punt on LG as Panny plasmas flicker and show green flashing on motion to my eyes (not talking about the 50hz issues) - I had a 2009-10 Panny plasma that I tried living with for 6 months before selling it on. I had something of a nightmare with Samsung CS on a LCD set a number of years ago, so vowed never to buy one of their sets again, so that only left LG.
So, what's it like? Well, as noted in the AV Forums review, the Achilles heel is black level response/contrast, which is enough to make images watchable, but could comfortably be outperformed by several edge-lit LCD sets. That, and the mirror reflective screen. However, motion is excellent, detail and colour great and the feature set stupendous. 3D performance was better than I was expecting, but then my expectations were pretty low. Glasses (LG's own) buzz annoyingly - take it this is a 'normal' feature of active tech? Have not done any gaming (worried about screen burn until the 100+ hours mark), so can't comment re: lag. My reactions are getting so slow that I may not notice the input lag anyway.
In summary, the LG feels (and I'd argue looks) like a premium TV at a less than premium price - I managed to get it free delivery from my local RS for £650, including a free set of 3D glasses. No TV is perfect (far from it in my experience), and I really wish black levels were better, but so far (note the caveat) this is looking very much like a keeper. Watching the Olympics on Freeview HD is hugely enjoyable, and that is without any calibration (just using minor tweaks on the default Expert settings re: keeping overall image brightness down while the set beds in). Likewise, movies are, well, very filmic. Watched Cloverfield last night and was blown away by how drawn into the movie I was and by how cinematic watching the screen felt. It handles 24hz flawlessly as far as I can see.
One other comment - temporary image retention seems to be an issue, at least from new. Can easily see trace images of menus, bars from 2.xx ratio movies, etc on a black screen when switching inputs. Disappears quickly, but noticeable none the less. Will this improve with time as the phosphors bed in? Anyone know, either with experience of this set or other LG plasmas?
Part of me wonders what the PM970 range is like, with the Tru Black filter. I had read some bad things about the 2011 filter from LG (did not add much to the black levels and was visible in daylight), so unless they have improved it, I doubt it makes much difference. Also, I think that chicken leg stand on the PM970 range is awful looking - much prefer the look of the PM670 range.
So, so far, so impressed. A great set at a great price. Oh, and Smart TV is excellent. Lovefilm in HD great.