For the OP :
Don't use SpecialCells(xlCellTypeLastCell)

It will not always give you the right answer.
If you deleteor clear a few rows/cells it will not update.
You must save the file first

I see. However, in this situation - where I'm creating a new worksheet on
the fly, inserting data and saving it - there's no chance of cells being
deleted or cleared. And once I spit out the 80 or so worksheets, I'm done.
It's the latency involved with searching each worksheet for the last cell
that I was thinking about.