Let's get this out of the way first: there are no offline editing capabilities. The actual editor is just the mobile web app embedded in a neat, little, native Android package. If you try to open an document without an internet connection you'll just get an cutesy error message. If you do have a connection (and exceedingly accurate fingers) you can open and edit your text documents and spreadsheets, but presentations are strictly read-only.
Google has provided more ways to filter and browse your docs than you could possibly need. You can pull them all up in a single list, narrow it down by collection (which once upon a time Google called "tags"), pull up your starred files, view only specific document types... the list goes on and on. And if all that scrolling and tapping doesn't catch your fancy there is an impressively fast search-as-you-type function.
We tested the app on a Xoom as well as a Droid X and, while we're happy to report it runs, it's certainly not optimized for Honeycomb. Launching the app presents you with the same single pane interface you get on the phone blown-up to tablet proportions. Instead of a list of collections on the left and files on the right you just end up with vast swaths of empty space. This is doubly frustrating when you attempt to edit a document. The tablet keyboard may be easier to type on than a phone (and easier still is a Bluetooth one) but, it makes little difference when selecting a line of text to edit or manipulating spreadsheet filters requires the fingers of a five-year-old.
The two big advantages of the native app are the homescreen widget and the ability to create a document from a photo. The widget is simple enough and lets you open the app, view your starred docs, or create new ones. One of the ways you can create a new document is by pointing your smartphone's camera at a bit of text and snapping a pic. The image is then uploaded to Google, where the Mountain View crew works some of its OCR magic that it's been perfecting under the guise of Google Goggles. The results are decidedly mixed. If you don't have steady hands don't expect much -- even slightly out of focus photos produce a doc with no text. If you can manage to score a perfectly clear image though, Docs does an admirable job of deciphering them.
If you find yourself constantly visiting the mobile Google Docs just to look up information in previously created documents and spreadsheets there is no reason not to install this app -- it's more than serviceable for reading docs. The lack of offline editing is extremely disappointing and unless you've got a tripod for your phone the OCR will prove to be rather unreliable. Still, the app is free, so what do you have to lose?