Gentlemen!, Gentlemen!, What are you doing?

vbNullString is a code construct. This has nothing to do with Excel. The gains, if there are any, are to be made when you have String variables set to, and compared to, vbNullString.

I don't know how values are held in Excel cells, but I am not aware of an Excel equivalent to vbNullString and I would not expect any significant performance advantage when one half of your expression is a cell value. Also, I rather suspect that writing to the StatusBar rather distorts the measurements.

I have just run a brief test and not seen any great difference but will do a proper one later.