Contrast Masking Variations

[Pat Minicucci]

I usually do contrast masking by hand (in a manner of speaking), versus using the PK Color plugin but am nonetheless impressed with the plugin's performance. Could someone elaborate a bit on the details of variance between Contrast Mask 1,2 and 3?

I assume the distinctions are in the amount of blur applied to the mask. Are there any differences in blend modes used? (And why does the final layer read out as "normal"?) Finally, is there any way to actually look at the mask that is being used?

Thanks in advance!