I knew about the advantages of Wetwork, but it wasn't until I joined a cousin and he was playing SWAT, and I got to play a few games of SWAT with my newly unlocked Wetwork specialization.
I was able to flank and actually assasinate a couple people, and got a triple pistol kill because I was able to walk behind people's backs without them noticing until their buddy died.
Smith likes this perky perk