Yes, it really depends on exactly what the OP is wanting to accomplish.
As I see it, the primary advantage of an app like Songbook would be the ability to have the app send MIDI data to the keyboard to select the desired patches or voices, but learning how to use the app and setting everything up could also be rather involved.
The primary advantage of something like Word or Excel would be the ease of learning how to use the app and entering the information, but it would be more limited in what it could do.
I was watching a concert given by Jon Anderson, Rick Wakeman, and Trevor Rabin, and Rick Wakeman had a very simple printed set list in a large, easy-to-read font that he was using, which could be created very quickly in a word processor or spreadsheet program.