The mask part only appears on female characters. I have no idea why.
But there's probably a mod that lets males use it too.
For a masked cowl nothing beats the Nightingale IMO.
Really disappointed when it didn't appear for males. I hate all apparel for the Dark Brotherhood in general in Skyrim. One outfit makes you look like a gimp, the other a bunch of rags.
It's because of the beards. They will show through the mask and cause horrible clipping.
There might be a way to make the beards go away and I'm looking into it for possible USKP inclusion, but that's a long shot, and might require heavy editing of all beards and mask so...
It's not that easy. I would have to explain to you how the meshes work in Skyrim (including partitioning) and that technical talk might be boring.
To make it work like hairs work, most (if not all) of the beards would have to be edited. And we don't even know if it will work anyway. You can't make beards go the way they are set-up now, else you would make the whole head disappear.
No it's not same concept. Nightingale hood is a full-head mesh. It covers the whole head, leaving no exposed parts. The way the system works, the character's head (and hair, beard etc) is removed when wearing full-face helmets.
Shrouded cowl actually leaves some parts of the head exposed.