I bought QuickOffice Connect when it was $15. They've released a few more versions, but it's still buggy and unfinished. I recommend against it.
I've discovered two major bugs that numerous emails to their technical support have failed to address:
Bug #1: Data Loss. If you are working on a document and don't explicitly save, your changes may be lost. The bug occurs when you context-switch and the lowmemory killer needs to swap QuickOffice out. QuickOffice does not properly handle being "shelved", so when you return to it, it will just load up the last saved copy, which will be missing any unsaved changes. You won't see any error or other message to indicate that you lost data!
Bug #2: Google Documents. The big selling point of QuickOffice Connect is the word Connect. It's supposed to be able to open and edit documents in the cloud on various different services, like Google Documents, Dropbox, etc. While it is able to open Google Documents and make changes, it is not able to SAVE documents. This missing feature is not stated anywhere, and the error you get implies that there is a network connection problem, not a bug in the software preventing it.
In summary - the application is a good idea, but don't spend any money on it, because it doesn't work. I hear Documents-to-Go is pretty good.