Coopster gave me one of these valves the other day, haven't fitted it yet. TBH they are very stiff so they don't turn that easy and it has a lip so the lever can't accidentally open.
Great Idea,
But I'll stick to my magnetic sump bung,
That way the old oil flows out much faster, hopefully taking as much crap with it!
Also, removing and inspecting the magnetic bung keeps an eye on things inside your motor,
Dan