I started using an iPad two years ago implementing a paperless cockpit with ForeFlight. This is after using a PDA plus PC based flight planning system for about three years. At that time I still had paper chart back up.
I have used this app all over the country into hi-density and country airports.
With the iPad though I went paperless all the way. I do recommend strongly a second electronic backup. For that I load ForeFlight on my iPhone. The view is small but just as good as the old PDA in days of yore. The ForeFlight documents section is a great place to store a check list.