I would agree with you about the audio based on other people's flat-panels, but I must admit I've been very happy with mine. It's a 6 year old 50" Panasonic Viera P50G20 (and, yes, it's a plasma!:), and its audio actually sounds really really good. Sure, it doesn't produce bass that you can feel in your bones, but that's what the surround sound receiver is for, though I rarely use it.
I dread the day I need to replace it because of the good audio and the picture is still amazing (it's in a basement, so it doesn't need to compete with direct sunlight). Hopefully the newer TVs are even better and I won't be disappointed.