When viewing the "Current Fields" in the Excel view, all of the time-related fields (time-spent, original-estimate, remaining-estimate) are shown in "pretty format" ala "5 days" or "6 weeks".
While easier to read, it makes it very difficult to use this data in any formulas.

Interestingly, the "Default View" shows everything as plain integers - which is less readable, but infinitely easier to do processing on....

Plain integers are good