I never really get the mentality of people expecting these types of shows to completely blow your mind or even come close to shows that get hyped in recent years with high & heavy production. Most of the time, you're lucky to be pleasantly surprised seeing older groups and all the better if the band actually exceeds your expectations. It's not like any group is going to sound or pull off a show like they would in their prime. They have more problems, 40+ years later from the age & health aspect to stamina and the normal technical difficulties.
The Zombies still pull off a good show, think it was 2002 when I saw them. Quite some time ago. 1967 it ain't & still I don't think you'll be disappointed. Nobody can tell you if you're going to get your monies worth because all of our standards are different. I'm happy shelling out the dough to hear the music & songs I love and to physically see the groups in a live atmosphere before it's too late.
P.S. You could hold off until May to see them on tour with the Yardbirds (Chris Dreja, Jim McCarty, Ben King, John Idan and Billy Boy Miskimmin) or when they unite with KISS for a special performance of "God Gave Rock & Roll To You".
