I have been a subscriber for 4 issues and have had no issues with the delivery and reading/format/navigation. I'm very happy with my subscription - just be sure to read the post in this board about archiving your magazines periodically so they don't disappear after the B&N auto-delete kicks in. The only other gotcha with Nook Magazines in general is that the Nook for PC software can't open the magazines -- so the only way I can view my magazine is on my Nook Color...sometimes it would be nice to also view it on my PC.
Thank you for your reply FantasyRider.
As far as archiving, have you ever tried to sideload a past issue and read it again? I also use Calibre and even download B&N books just to have a backup.
I don't have Nook for PC, but I do have a Nook Classic 3G, which seems like a waste for National Geographic. Not sure it's available for that anyway.
FantasyRider, does the E-Magazine for National Geographic arrive on the NOOKcolor with all beautiful photos intact?