"With Google Drive, a double-click on a Google Doc opens the document in a browser" - Woopie. I can open a .DOC file and Word opens up on my desktolp or laptop. So?
And it can view a bunch of type. I don't know when the last time someone sent me a Photoshop PSD file and no one ever sent me a PAGES file. Anyone actually use that? And as for Autocad, if you aren't in that business you don't need it. If you are, you already have Autocad installed.
So again. Big woop.
Finally do you wish to put everything in one basket? If Google Apps [or Google Drive] goes down - and it has enough times - that isn't good.