First, the file that is synced to the local drive that has the most recent updates and edits will be in Google Docs format. Google Docs files in Google Drive are actually links that open Google Docs for editing online. If you happen to be offline, those links in the Google Drive folder would be useless.

There are a couple of ways to work around this issue. First, you can configure your Google Docs for offline access, and you can use Google Chrome browser extensions to enable you to edit Google Docs files offline. Another solution would be to save the file back to its original format after editing it online so that it will open locally in its native application as mentioned above.

That brings us to the other potential issue--file fidelity. Google has gone to great lengths to maintain formatting when converting from Microsoft Office formats to Google Docs and back again, but it still leaves a lot to be desired. For basic documents that just have text, with maybe some bold, italics, and underlining, or simple bullets, it may not be an issue. However complex documents that include things like a table of contents, footers, headers, and footnotes are likely to get mangled and require a lot of manual repair when switched back to their native format.

Businesses and consumers that already work predominantly with Google Docs need not worry. It will just be business as usual. But, those who may think twice about using Google Drive due to the need to convert to Google Docs formats to edit online.

Ultimately, cloud services from Google, Microsoft, and Apple tend to be more proprietary, and make the most sense for users that already work in a Google, Microsoft, or Apple-centric environment. For broader cross-platform integration, the more independent offerings like Box, Dropbox, and SugarSync may be the better choice.