From the moment you launch this mobile office app, it feels like it was made for the tablet (because it was). By contrast, the other three mobile productivity suites in this roundup--including Documents To Go, with its recent Honeycomb updates--look sparse and ill-fitting on a 9-inch display. Quickoffice HD Pro's tablet-centric menus drop down from the top as you would expect menus in a full-screen app to do. Objects in documents, such as photos and text boxes, include handles for easy resizing and repositioning, just as in their Microsoft Office counterparts. At every level, this suite is the best Android editing environment of the bunch.
In addition to Google Docs support, Quickoffice HD Pro includes support for Box, Dropbox, Huddle, SugarSync, and Apple MobileMe accounts. Hands down, this is the best lineup of cloud options among the four apps.
In its Microsoft Office formatting, Quickoffice HD Pro is on a par with ThinkFree and Documents To Go, and worlds better than the Google Docs app. It also reads PDF files, and it can open and browse zipped files as well.
If you have an Android tablet and you're serious about getting work done on the go, you'll want to grab two things: The first is a good Bluetooth keyboard (or a compact USB model, if your tablet supports it). The second is Quickoffice HD Pro.