Originally Posted by mag99:
“I don't think that Joseph is as demanding a role as Maria - not as much stage time or songs therefore it's probable that the winner will be expected to do all of the shows. Having said that I took my daughter to see the Friday matinee of Joseph when Ian 'H' Watkins was playing Joseph and it was the understudy much to my daughters dissapointment who had been looking forward to seeing H from Steps.”

That is always a huge disappointment, especially if there is a "name" in the cast. We have all probably experienced that at some point. I admit to often going to see the "star" as much as the actual show and don't think I'm alone in that. This is something that ALW and co must surely be aware of.
Therefore to not leave people disappointed, I think that they have to guarantee as much as they can that there is more chance of seeing the star than not and cast somebody with the appropriate experience/stamina to do a prolonged run. Also, I think if they take a regular day off(Lesley Garrett took every Thursday off in Sound of Music) then people are entitled to know this, to enable them to book for another day if who they see is important to them.