If you were to look at DataViz' own support page, you'd see it looks a little light for features:
- Now supports Microsoft Office 2007
- View Microsoft Word 2007 files and attachments - read-only
- View Microsoft Excel 2007 files and attachments - read-only
- Various bug fixes
Now, I've been a loyal Documents To Go user since the first Mac incarnation (version 2.002!). The suite has gone through changes that turned it from a basic "view my documents on my Palm" application to a full fledged "who needs a laptop" suite. It seems to me that DataViz must feel the Palm OS market is dying out, and they want to milk us for all we're worth before we jump ship. It's not fair, and upgrading from 9 right now is not a really wise investment at this time.