On AVForums review it says for lag on the PK350 The input lag time was about 50ms which is surprisingly high, especially for a plasma. I have reviewed LCD displays with input lags from 10 to 80ms but the majority of plasmas that I have tested have very low lag times so I'm not entirely sure why the current crop of LG plasmas have such high input lags. Having said that I wasn't aware of the input lag during actual game play but it might be a little slow for hardened gamers.
Personally as a gamer I find anything over 50ms as being too high. I had the PK590 and while at first I was happy with it the high lag made gaming hard. You couldnt see the lag but 'feel' it.
For power AVF had this to say Like all plasma displays the PK350 uses a self illuminating technology so the power consumption varies with the content shown on screen. Therefore high contrast white background material will use more power to create an image whilst darker scenes will use less. The highest measured figure with normal viewing content was 300 watts, the lowest was 180 watts and the average was 220 watts. The consumption figures at 0, 50 and 100 IRE rasters in the calibrated picture mode were 150 watts, 210 watts and 350 watts. The PK350 doesnt have the most efficient energy consumption, even for a plasma but its average consumption number is quite good.
Sorry mate no U30 on display.
Popped into the store and there isnt one there. Had a bash on a S30 and it felt the same as my VT so I would assume the U30 would be the same. Its generally thought the lower range models have less input lag than the higher range. This does show on the review of the C3 and S30 Vs the VT30.