It's a shame about the limitations on iOS. The Android Google Drive app is much better (as you would expect).
Hands-on with the Google Drive for iOS app: mostly read only « Ars Technica
Google Drive for iPad and iPhone hands-on « The VergeThere’s just one problem: once you get files outside the Google Drive app, there’s no way to get them back in with edits other than by emailing them or sharing them through another cloud service (like, say, iCloud). That sort of pain is to be expected with Cloud storage access on iOS, aside from Apple’s iCloud. Microsoft’s SkyDrive suffers something of the same problem—it integrates with other applications, including Apple’s Pages, for opening documents, but once you do, your edits get stuck back in a different document hole.
Google Drive for iOS hands-on « EngadgetIt won't take long for you to realize that there are a few major features missing here. There's no way to delete a file. Even worse, you can't upload any files from your iPad or iPhone from within the app, and you can't create new documents, either. As you may have guessed, that means that there's absolutely no editing functionality built into Drive for iOS. Google's support documentation encourages you to use the actions button when viewing a file to open it in another app on your device or view a document in Safari. The latter will let you edit the file in the Drive web app, and that's as good as it will get for would-be road warriors using Drive on iOS. For reference, Drive for Android not only allows you to edit files, but you can also view collaborator's changes in realtime — just like the full desktop web app.
First and foremost, the most disappointing observation is the lack of editing on the iOS version. For such a large-scale cloud service, the concept of only being able to view your documents or other files without the ability to edit them is completely unacceptable. In fact, speaking of cloud services, Google has decided to allow you the opportunity to open your Drive docs in other iOS apps. In three clicks you can have your doc ported over to QuickOffice, Dropbox, Box.net, Evernote or whatever other document viewing program you like to use. But this doesn't mean you can actually edit your file -- text docs port over to other apps as PDFs, which means they're still stuck in view-only mode for every program we currently have on our device.
If you really, madly, deeply want to edit your docs, there's one way to do it -- click on the share button on the top right corner and choose "Open in Safari" to pull up the Google Drive web app that's been available on iDevices since the service launched. Indeed, this completely defeats the purpose of having a standalone app at all; you're better off keeping that web app shortcut on your springboard and accessing your files that way. At least it takes less steps to begin editing your docs.
The absence of this crucial feature in the app itself might be more understandable if it weren't for the fact that the Android app has the editing functionality built-in (although it essentially wraps the web app to do so), and there's no technical restriction preventing Google from actually adding it into the iOS app. On a good note, that means we may very well see this included in a future update.