Smooth/soften edges

[mitcorb]

Here are several questions that may seem naive, but I have been using this feature sparingly for some time and cannot determine the advantages and disadvantages:

Does the process of smoothing/ softening edges help reduce the file data?
I am aware that the process aids in rendering, but does it improve navigation?
Is it always better to smooth soften as you go in the model?
Once you have smoothed the model, is it possible to or is it ever necessary to revert the model to non smoothed?
And, what if, when using the eraser tool with the control button, you select already invisible edges? Do these get resmoothed to a greater degree than before?

[mitcorb]

Ok Thank you modelhead.