Getting this plugin installed initially was a pain (the Google API steps were not very clear), but after that it seemed to work well. I had it running successfully on two sites.
After the first week, the first site stopped working. No more backups, yet there was no notification of failures or error messages. When I try to run a backup manually, I get a blank screen, which is possibly the most frustrating thing for a user to see.
Second site still works, but I'll be looking for another plugin.