Using the SugarSync Android App (Ver 3.6), I sync'd an MS-Word .docx file to my Samsung Galaxy S II. The file gets deposited in \sdcard\My SugarSync Folders. While still in SugarSync, I select my phone from the My Devices section on the main page. I tap on the My SugarSync Folders, after which I see my file listed. I tap on the file and it opens in QuickWord (from QuickOffice Pro Ver 5.5.209 - QO). I make a change to the file. When I tap Save, I see the message "Error - Could not save the file." I click Cancel, and see the message "Quickoffice Pro - Unable to save file" after which I can only click "OK." If I select "Save As..." I CAN overwrite the open file, but I have to navigate back to the My SugarSync Folders, which IS a solution, but a bit cumbersome and annoying.
The phone came pre-installed with QuickOffice (Ver 4.1.20110711.67 SAMSUNG). When I perform the operation described above with this stripped-down version (note that this is QuickOffice, not QuickOffice Pro) I AM able to save the file directly.
Finally, the User Guide specifies that "after the file closes, SugarSync detects the change and asks if you would like to upload the file to SugarSync." This doesn't happen with either product. I have to manually select the file and Re-Sync.