It synced down my Google Docs files. Except it didn't. They're not, say, Excel files, which I assume the average user will expect. AFAICT they're shortcuts into Google Docs, which I didn't really need since I know where those are already, to a close-enough approximation. So now on my local drive I have two classes of spreadsheet. Real spreadsheets and links to my online spreadsheets, which kinda mirrors normal hyperlinks to online spreadsheets, so we have two classes of those now as well. I can't really predict what will happen if I download the file as Excel and put it into my Google Drive directory. I guess I'll have two files, but will my newly created Excel file be a new doc online? What will happen if I delete the local links?
Created a text file in my local drive. Waited. Nothing appeared in Docs. Right-click the file to "sync", no menu item. Right-click the directory, no menu item. Click different Docs directories. Nothing. At some point, it appeared. That's a temporary issue and can be fixed, but those details count.
Dropbox/Sugarsync feels a bit more predictable. I'll sync, that's it. I have a button I can push to make it do something predictable. Seems less magical.
File sync is a square hole. Google Docs is a round peg. Feels like the reasoning behind this is boardroom-strategy-level, not user-level.
Right now Dropbox/Sugarsync will keep my business. Earlier today I put one minute towards grandfathering a Skydrive account to 25GB free, just in case that proves useful. Hope I'm wrong and Google Drive feels more useful tomorrow.