Hi,
I have the same telly as you, but it's been consigned to the conservatory for the last couple of years, since I needed a larger screen (40) for my lounge. Recently I had to move the Panny back to the lounge, because I had to return a new tv back to the retailer,due to a fault, and had no tv for a few days. I'd forgotten how great the panny was, and still is. The sound is better than any tv that you'll get nowadays, and the picture is still fantastic. if you want the same size tv, then I wouldn't bother, as you'll be disappointed, but if you want a larger set, then keep your Panny, as a second tv, as you don't want to sell it for peanuts, it's too good for that. I have a Sony ex503, and it is a great tv. The only difference is, the blacks are better on movies, and because there are alot more settings to fiddle with, you can get a more vibrant look to your viewing, and the size of the screen gives a bigger impact. Sound on the tv is quite tinny initially, and you have to take the treble right down to zero, for half decent quality, but it's much better played via a hi-fi or dedicated theatre system.