It's not a "piece of junk", the unique cone shaped valve insert is susceptible to damage if a chunk of grit/rust/crud gets into it, scoring the plastic cone and causing a slight (but ungood) leak. If your gas is clean, tank isn't rusty, and the filter sock is good this should not happen. I have this type on a couple of tanks, have never had a problem. There are single and dual nipple versions, I don't know why a single PN would cover both.
The bung threads are different sized from what the 4-hole rubber seal type petcocks fit. I don't know if any other petcock would be usable.