Has a great UI which allows you to crop documents (even pages, odd pages, all, ranges). Once you turn off the on-screen menus, relax the gestures, and set it up for vertical scrolling, it's perfect for reading software dev PDF ebooks on an iPad mini in full page portrait mode. Good folder support for organizing stuff within the app, or you can even drop a set of folders onto the app's container within iTunes to sync a bunch of content at once. Some of the "download from the web" type tie-ins seem to crash the app. That seems to be a work-in-progress that I don't really care about anyway; open PDF's from within Safari (not Chrome), tap on them, and you can "Open In..." ezPDF to get it into your library on the fly.