John,
I have used my IPad for 5 years and will never go back to a laptop just to display leadsheets. I use two different programs.
1. UnReal Book
2. Good Reader

Each has it's own benefits and cost under $5.00 each.

My iPad also serves as a DJ system when needed. I have over 6000 leadsheets on it and we'll over 500 MP3s when needed. I keep it backed up and actually have a 2nd IPad just in case.

Deane