The Maptech software, which runs on any computer, has CDs which contain the same information (plus) as the Chartkit chart books for the same area. That is, the disk for region 2 from Nantucket to Cape May NJ contains ALL the NOAA charts not just the ones for the ICW. That makes, in my opinion, the electronic charts primary and the paper charts secondary.
Each region, with hundreds of NOAA charts takes up one CD which would be 640 megabits max. The operating program is much smaller than one disk so 20 gig should be plenty for extreme detail of all US waters.
All the disks for the east coast from Nantucket to Key West, four discs, cost less than $800 (less that $200 each).
Since the Maptech program runs on any computer, I have in on a laptop and take it to any boat.