I like to run the open breathers as they are easier on the seals. Whether they offer any performance benefit or not -- I couldn't say. If you run an open breather setup you can cap the TB/valve cover connections, but only then. Otherwise you are asking for trouble.
I saw the explanation of how it works -- but I didn't really get why unmetered air vs. metered air in the crankcase makes a difference. I think that was some of the questioning earlier, and I'm wondering the same.
Myself, it would seem like if you are going to run an open breather it might be a good idea to cap the nipples on the TB [and valve cover] so you don't let unmetered air in the intake. But maybe I'm thinking wrong? I've never had any problems, so I am just tossing an idea out...