Maybe not the PC but Excel certainly does care how big a formula is. I have
seen many a Workbook forced to switch calculations to manual because of poor
design. That's a false reading waiting to happen and catering to bad design
when they should fix it. By doubling up the VLOOKUP with an IF and ISNA
Function you doubling the calculation needed and the recalculation time. Not
very prudent spreadsheet design. My way, is as I said, less typing, far less
calculation time and hence more efficient for both Excel and the user. You
wont notice the difference until it's too late. If that doesn't warrant the
word "efficient" you must use a different Dictionary to me.
But hey, I'm not here for a pissing contest and to be drawn into by
nit-picking.