I saw the Popular Science magazine on the front page of the app store the other day, and remembering how much I loved reading it when I was a kid I downloaded it. After spending 15 minutes flipping throughout the preview issue I promptly subscribed for a year.
The download of the first issue was fast (only about a minute or so) and then after a short bit of 'processing' (I think it was decompressing images and such) I was able to start reading it.
I'm totally in love with the format. It's quick and easy to navigate, every single page has full page graphics behind it that you tap once to see, tap again to see the article. Also a lot of the articles are 'see through' so you can see varying amounts of the images while reading.
Of course the one thing I love is that it is FAST, no delays or pauses, even when playing videos.
I highly recommend it to anyone who has an iOS device.