Electronics are primary for me, with a paper backup for local flying.
On a recent trip from Idaho to Alaska, I found I would need roughly two dozen charts and several books - too unwieldy for a Cub cockpit. So, I went with 3 electronic devices: Garmin GPS in the panel, iPhone, and an iPad, with all charts and books downloaded ahead of time.
BTW, XM weather works fine in Idaho, but was mostly useless in Canada and Alaska. I think the satellites were just too low on the horizon. I had to turn off the feature to stop the annoying loss of signal warnings. Perhaps repositioning the puck antenna would have helped, but not something I wanted to mess with during the trip. I'm curious if others have the same trouble.