I would think programming styles would be the big reason to use something like this, for example if you use NoVarsInStrings and Explicit.

Using this Const() UDF would hardcode a value into a function call, as seem by some of the examples, that value could be a complex process.

Otherwise, you would need to DIM every constant variable that you use, and would have also be sure to reuse those variables later on in your script.

Bryce