I have the TH-37PX80 and I am still amazed at what a good tv it is (for the money). I hope that you enjoy your tv as much as I do mine.
It's my first flat panel tv and I have read lots about the sound quality on flat panel tvs, that it's not as good as on a CRT or a surround system etc, but honestly I have been very pleasantly suprised by how this tv performs for sound, and I think that you might be too. Obviously it doesn't compare with a surround system, but even the bass is decent. I have my tv quite close to the wall (30cm or so) which may help. I was considering that a surround system would be my next essential purchase, but now I've heard the tv I'm not in such a rush.
I think that I read that you also have the Sony bdp-s550. I have one of these too. The viera link/bravia sync features work between the player and the tv. I.e. turn on the blu ray player and the tv automatically turns on. I have to say that as a combination this player and tv works very well. I did want to go for a panasonic blu ray player, but I needed analogue outputs for my surround amp, and couldn't quite stretch to the panasonic bd55.
The quality of blu ray from the Sony is stunning (to my eyes). This is true of DVD playback too. I tried comparing the playback of a dvd, which I have two copies of, on my older sony dvd player with scart output, and the same dvd on the blu-ray player and the difference is like night and day. (sorry this is slightly off topic!)