I decided to try QuickOffice. It has an excellent file manager, and good integration with dropbox, which is important to me. I have found a few issues:
One large complex spreadsheet I use has graphs embedded. They don't display. However they are not damaged, and show again in Excel after a sheet has been edited by QO.
Saving a spreadsheet back to google docs loses some formatting. I don't do this often, but there you are.
A significant issue I've found is related to text entry into cells: it really wants you to enter numbers, and shifts the keyboard immediately into number mode regardless of the cell type. Furthermore once you correct this and start to type your text, it pops back to number mode every time you hit the space bar in between words! Clearly this is a bug (I'm told the iPhone version does not do this) so I would hope to see it fixed soon.
I've only done limited Word testing so far, but it seems easy to work with.
- Tim