It's okay. I've been using it for several years now, on various iPads. To me, it's about the best e-book format I've seen, altough I've generally fought them, based on prior bad experiences. I am finding, as I get older, the pictures in paper copies are getting smaller and smaller. It HAS to be the magazine, right?
Pros:
You're not wasting paper.
You can zoom in to the images to see more/better details. The picture quality in the ezine is generally quite good.
Once the ezine is downloaded to your device, it generally works pretty quickly.
You have a library of all the ezines you downloaded to your device.
The subscription counts as a full subscription, giving you access to all the digital extras someone with a paper subscription has.
Cons:
ezine download times are sometimes long. One month the issue populates quickly while others, I find I have to bring the iPad into the office next to my router to get speed to improve, and even then, leave it there all day.
That's about all the cons I can think of.