There is an advantage to having the oil drain quickly from the engine, it helps evacuate the dirt a bit better. That's part of the reason it works best on a hot engine. The drain hole looks smaller on the valve than the normal drain hole. You would also want to be certain no part of the valve is in a position to get busted off by road debris. otherwise it sure looks handy.
Do not bother with that gimmick. If you run over something and that lever opens...you are dead.
You are better using the stock bolt as said you need the full size to drain out the oil properly, always with hot oil to get any sludge out.
If you have stripped the head, you need to replace it with a new bolt and use a 6 point socket or 6 point wrench when changing the oil, not a 12 point or open end wrench as that is where most people mess them up.
Be sure and get a new crush washer too. You can reuse the crush washer @5 times.
Thanks for the answer and the advice. I am going for it as long as I have enough room to screw it in, because I change my oil every thousand miles and I like things that make life simple, if you're scared of it opening they sell a little clip to lock it but I've had this before on a 4 wheeler and never had any problem with it.