Advantages: The actual valve is very robust, is in the closed position really tightly and holds probably forever, when you move it from time to time. Since the lever can be unscrewed, it can be installed in hard to reach faucets.
Disadvantage: Since the lever is made of plastic and a square recess comprises the actual valve, it is stretched with each use slightly and then decreases at some point no longer with the valve. After a few months (depending on frequency of use) can the valve so the lever no longer move. The screw is then quite corroded, and therefore it is then difficult to solve them.
To fix the part you can again buy (if it still gets) and simply replace the plastic lever. The actual valve's usually still okay.
It would therefore be useful if either the metal lever would be (but would conduct heat well -> risk of burns) or you would get the plastic levers appear as a spare part. Both I have not found.
