Like Microsoft's OneDrive, Google Drive integrates easily with Windows Explorer: Download and install a local client. You can even make Google Drive -- or Dropbox, for that matter -- your default save location in the desktop version of Office 2013. Unfortunately, you can't do that in Office Online.
My two big disappointments with Google Drive: First, Google has been at this game a long time, and the apps have grown in a gangly way, much like desktop Office. You won't find any of the elegance or unifying logic in the Google Drive apps that you'll find in iWork for iCloud (or Office for iPadiPad, for that matter). That said, if you know Office 2003 with its pre-Ribbon menus, you'll feel right at home with Google Docs, Sheets, and Slides. Alles zu iPad auf CIO.de
Second, I'm still not comfortable with Google's unabashed approach of scanning all of my documents in pursuit of ad clicks. Unlike some companies (and governments) I could mention, Google is honest about it. But it still makes me queasy.
Scoring the cloud productivity suites There is nothing so personal as a personal productivity suite. Thus, assuredly, your results will vary. If your organization needs an online productivity program that won't mangle Microsoft Office documents, the compatibility score may outweigh all other considerations. If you're going to cloud productivity apps to save money, then value rules supreme. But be aware of the fact that we don't know, long term, if Apple will charge for its suite.
Google Docs is a decent word processor, but Pages for iCloud is superior in many ways. Word Online comes with many features that aren't included in Pages for iCloud, but in some respects -- for example, handling pictures, text boxes, tables -- Pages for iCloud runs rings around Word Online. The ability to create and run scripts in Google Docs means it has been -- and will continue to be -- extended in many useful ways. None of the editors come close to the depth of features in Word 2013, nor do they approach Apple's Pages for OS X.