Looks useful! Their iRig adapter is nice, and the Amplitube app is one of my favorites (pitch-consistent speed control for free!). As long as it's not too expensive I'll probably look at getting it. Carrying my iPad instead of a bunch of printed sheets of music would make life a lot easier.
I like it because you can turn the pages with your foot. I don't like scrolling while playing, and to be able to read printed tabs (at my age) I have to magnify them, which means turning a lot of pages in a song.