You will like it, they play a lot of older stuff but still mix in some new stuff. The sound is really......REALLY good. Only show I saw on TV that was better (sound wise) was Megadeth but I am pretty sure Mustain was not singing.
I have the British Steel special they did on HDNET recorded and then transfered to DVD. I thought it was awesome.
Big Priest fan here. They are amazing in concert. I missed out on a chance to see them this last fall because of a stupid broken leg.