The Lower Antelope Canyon tour is definitely the highlight of our 13 day 7 parks schedule. We enjoy the tour a lot and will treasure it for our life.
The only problem is we paid too much for the tour. In fact, we can save a lot (may be 40%) by booking directly through the Ken's or Dixie's Antelope tour website. Also it will save you a lot of hassles going through agents of agents and paying double commissions (Viator, National Park Express).