I decided to buy Polaris Office 4 ($10) to give it a try.
So far, in limited testing, it seems to do a fairly good job importing Word, Excel, and PowerPoint documents, with reasonably good fidelity. Of course, I doubt that it would provide functionality for documents with macros, VBA, etc., but for basic display and editing, it seems to do well. One small issue (likely common to any non-Microsoft app) is the occasional missing font, in which case text may be rendered in a substitute font. As you might expect, most of the modules (word processor, spreadsheet, presentation) provide only basic functionality for data entry and manipulation. You won't find ore advanced formatting features, although some basics like text formatting, borders, and lists are included. I have not yet tested creating or editing a doc in Polaris Office to see how those edits show up in the native desktop applications.
I was really interested in perhaps using the tablet to do presentations, and it seems like this may be workable for simple presentations. Some transitions are supported, but it seems to get tripped up on multiple transitions per slide. On the whole, though, the fidelity is decent even for more complex graphics and text, so my cleanup time as been minimal so far. In my case on the iPad, Apple's Keynote app may be better as a presentation app, though slide cleanup would likely still be required for decks imported from PowerPoint.
JKG