This has got to be the best 37" LCD TV on the market. I have had it for 1 month now, so am well qualified to give a users opinion. I have it set up with a HD DVD (1080i) player, Blu Ray (1080p) player, Sky+ and Freesat (thus making use of the included freesat HD tuner!). Firstly SD: it depends on the channel. If the broadcast bitrate is poor, then no display panel can do much with it. In general however, PQ from Sky+ via Scart is very good. A friend of mine thought he was watching Sky Sports HD last week until I told him that I don't have SkyHD!! It was regular Sky Sports!
HD images are amazing. Blu Ray films are rich, clear and vibrant with incredible detail. Colours are realistic and deep. Motion is smooth, although I find that IFC set to max gives a little of the over-processed look...mid setting is much better. Blacks are very good for an LCD also!
To sum up...this is another fantastic LCD from Panasonic...the best LCD manufacturer in the business!