Almost completely unusable.

I dont know if its the servers or the app, but since the major redesign with the smart lists, etc, I have been unable to reliably download comics with this app. They will download a couple megabytes and hang. The best way to download a comic is to start reading it, because it will try to download the next page while you are reading one. Of course, it will hang, but when you go to turn the page, you can simply wait a minute or so and it will finally time out and try again! At that point there is about a 70% chance that it will complete the next page instead of timing out again. This is great at making your comics feel worth the money because each issue takes about 15 to 30 minutes of overhead, waiting for it to load time.

Lefty the Pirate about Comixology - Comics & Manga