Theoretically, paper is best, but when you're disabled having everything you need on the computer is a real boon, plus you can vary the font size, use search features, and still keep the place you were at, have bookmarks, make notes and annotations, etc. So though I have a lot of Seaby/Spinks, the relevant values for all my coins are in the database where the changes over time can be compared at a single glance without having to find and prop open 10 copies of the catalogue (probably not something anyone who only uses paper would ever do). I get CCGB annually, the Kindle edition.