If you're older, it's a must see! I saw people 40+ having a great time, dancing to the music, dying to give standing ovations and as we left were saying "let's watch this again!" Maybe the music brings back the good times.
I thought the music was great, but something about the story line, jokes, stage props, intermission and some singing left me feeling unsatisfied.
Tip : We were able to get very good seats for $50 at the "tickets half off" place where Coca Cola is on the Vegas strip.
Tip2 : Don't know if this is allowed, but I saw people spotting open seats and changed to them during intermission.