Shaun,
I've had one for just over 2 years. The original purchase was based on a TON of research and I have been very pleased with the unit. I've also kept up with the research since. There are other decent choices out there, but for this particular segment of the TV market, what I've read is that Sony is pretty much regarded as the benchmark.
If you can control yourself a bit longer, the new ones (5th generation) will be available in June/July Part of the model # for the 50" and 60" is "A20". They will offer a dynamic iris (current models use a fixed iris).
There's a long technical expalnation that put me to sleep, but the net is that it will improve details and blacks.
