Just so that you don't feel left out...

Here is the reason from the link given by Ed

"When your scenarios will require the improved open/save performance of the
binary file format, use XLSB; otherwise the benefits of the XML format often
outweigh the (usually unnoticeable) performance benefit of this format."

Unless you have issues with time taken to Open and Save... default formats
are good enough.

Also as my company's dress code policy says "in case you are wondering
whether I shoudl wear this or not then probably you should not" :-)

You should use this format only after you understand the benefits or after
experimentation with few spreadsheets... do keeps a xlsx copy.

"Ed Ferrero" wrote:

Hi Kevryl,

I assume you have seen this?
http://blogs.msdn.com/b/excel/archiv...20/671995.aspx

Ed Ferrero
www.edferrero.com
.