We tried to move to Google Drive but are about to go all in for Dropbox for Business. The Google Drive desktop sync client (for Mac at least) is just not reliable enough. Make sure you trial Google Drive first.
The Google Drive sync client is lacking features for business. But third party Google Drive sync clients like Syncdocs http://syncdocs.com make it better than Dropbox.
Not features; reliability. We have fairly modest Enterprise® requirements, but we do shunt around medium-size files quite often and expect them to be synchronized around the office as well as Dropbox manages it.