I went to a Conference like 15-16 years ago and they hired Sammy to play a concert. (they always had decent acts at those conferences like Collective Soul, Huey Lewis, Goo Goo Dolls, Styx, etc...) I have to say....Sammy and his band Cabo Wabo were pretty fun to watch. You can't compare him to David Lee Roth like everyone else always does. They're just different styles of rockers.
What's crazy is bands like Journey who cruise Karaoke bars (I know that's not how I really went down) to find cookie cutter cover singers of their songs who's mimicry could fool someone who didn't know it wasn't Steve Perry.