I've seen 3DG live before. They put on one hell of a show. At this point in the game, however, I think I would rather see Adam solo...
Okay, after just seeing Three Days Grace performing with the new singer, and even though they did put on a kick ass show, I really have to say that the new singer kind of pisses me off. He twists around the meaning of the music being played, and while most of the material that was performed was when Adam got sober, all the new singer did was talk about how fun it was to get fucked up on drugs and shit.
That's what happens when the lead singer leaves a band where he wrote all of the songs. Your replacement can come right in and sweep the meanings away from the songs, or attempt to anyway.