Yes they are. If I was Vivian, and I was touring and had the chance of playing Dio songs every night or songs like Photograph, Too Late For Love, Animal, Women, Let It Go, Bringin' On The Heartbreak, Another Hit & Run, High N Dry, Rock Rock Till You Drop, Lets Get Rocked, Make Love Like A Man, Two Steps Behind, Stagefright, Hysteria, etc.. I know what I'd be choosing.
(And yes, Def Leppard have been opening most of their shows on their last tour with the entire side 1 of High N Dry, Let It Go through to Switch 625).