Buying a 13.3-inch e-reader (A4-sized) is a major investment typically aimed at professionals, academics, or musicians who need to read full-sized PDFs and sheet music without scaling down. While "Good e-Reader" formerly produced its own 13.3-inch model, the current market is dominated by more modern, high-performance alternatives available through their store and other retailers.
For those looking for the largest possible digital paper experience, the following models are the leading choices: Boox Tab X Review - eWritable