Hi George
Bob asked for "major differences" and what's major is maybe a question of
what you use it for. The two (three, including 2003) are certainly
compatible.
I use Excel at times for washing huge lists of data, manually or by code,
formulas rarely involved, but mostly I do pretty small spreadsheet apps with
formulas, userforms and code. For this use, the versions (2000, XP, 2003)
are identical to me, and I use all three, almost at random without thinking
much about which one's running at the moment.
However, I know users who work with heavy big spreadsheets stuffed with
formulae, see XP as a huge improvement, and I don't doubt this. I believe
both memory handling, calculation handling and function assitiance is far
better.
So if this is a "worth upgading ?" question, yes, no, depending on what you
do with her. Major differences, well yes, no,... But a file made in one will
run on the others (with very few exceptions, and those would be VBA code
related).
Best wishes Harald