When Should I Use Local Contrast Enhancement?

I found the page on local contrast enhancement using an unsharp mask fascinating and have been impressed with this technique.

What confuses me is that it seems applicable for almost any picture and makes them, to my uneducated eye look sharper even if they are not hazy in the first place. Can this be used instead of ordinary sharpening? Should one use both in different layers for the hazy picture? Or is it better to use typical sharpening with typical settings (like 150%, radius of 1, etc.) and save this for hazy type shots.

My opinion is that this technique could be used in addition to ordinary sharpening, when necessary.

All photos require some sharpening upon enlargement (whether this is done by the camera or by the user after RAW conversion), but not all photos need the local contrast enhancement technique. One situation where I would say it's especially useful is if one has to shoot through a window, since this ordinarily results in a dramatic reduction in local contrast.

Be careful not to overdo it though. Try using the haziness of a photo to your advantage instead of trying to hide it. Haze can be a very powerful tool for highlighting distance, or adding an element of atmosphere. I think it's always best to make the most of any subject.