totally agree Graham,
another good ACDC band is Hells bells who regularly do the Bulldog.
The good thing is its basically a Greatest Hits Concert which is great if you dont know the bands that well. Most genuine concerts nowadays are just promoting the latest album (sorry must get into the 21st. Century: CD, Download etc) and unless your a devoted follower you dont know the songs.
As for the comments about the tributes not being as good as the originals, you want to hear some of these guys sing and play. They are really good. Noone can be as good as the Flames at Gaydon though, get up and dance you funky Stretchermonkey!