I installed one many, many years ago on my old Mercedes (owned car for 26 years). The reason I did it was because the drain plug on the 450 engine is 24 mm (huge). When you removed it, the oil came out so fast that it would overflow the concave portion of my drain container because the oil would flow out of engine much faster than it would enter container. The 450 engine holds about 10 quarts of oil.

The valve works well. Never had a problem with it. It never accidentally opened and does not leak. Now I have a lift and a reservoir with one of the extendable funnel things on it so the size of the drain hole is moot. But I keep the valve in that engine so I don't have to anneal the copper sealing gasket.