Hello, qnc
Sorry about the above miscue.
I've been using a Psion Series 3C with PSIMac software. Works fine with Excel and Appleworks spreadsheets, as well as MS Word. The screen is much more adept with spreadsheets than a visor (or Palm), and has a zoom function which allows viewing a useful chunk of the spreadsheet (say 10 columns by 8 rows). The Dataviz translators carry over some formatting and most formulas (probably not macros).
I've also tried Docs to GO; well intended and designed, but I found it useless because of the limited viewing area on the Visor, and the #!/&% grafitti input.
Psion 3C's pop up on eBay pretty often, seem to be going for $100-150 these days.
There are some minor tricks to making it work with OS9, but it can be done easily.
Problem is that while the Psion 3C is still a capable piece of hardware with an elegant and robust OS, it is long out of production. The later Psion's had mediocre Mac support; don't bother.
Bottom line: I run a G3 Firewire PB with OS9.1 and routinely swap spreadsheets (AW and MSXL) between the two, and I'm able to generate and edit on either machine with no worry about incompatability. Most importantly, I can SEE what I'm working on with the Psion 3C. If you value true utility over having "the Latest", consider a Psion 3C with PSIMac.
Hope that this is helpful.
Regards,
Brian