Why use Range.Formula in VBA for Excel 2003 instead of Range.Value?

In terms of values of data:

Imagine you have integers, doubles for certain calculations and if you use .formula you gonna get screwed. Because .FORMULA always return a String. (Any value set to .formula without is a plain value not a formula) Unless you have exception handling and the extras ready in your code. Whereas .VALUE returns your data's data type as you expect them to be.

In terms of retrieving formula: Value is one way road in case to set formula but not to retrieve.

So you see these methods are introduced for a reason and help you to work with right properties you require. :-)