I am very comfortable with the double D. It's not really a hassle, in my mind. I've worn some ratchet strap versions where the ratchet seemed too long and kind of dug into my neck after several hours. Maybe just a bad design or not enough padding. Sometimes I ride all day and strap comfort becomes important.
I've heard some good things about the magnet type. But have never had opportunity to try one.
Few people understand how a properly fit helmet should be. And, in my experience. If you offer them a properly fitting helmet, they won't wear it. That was me for a number of years. Until I got into the fire department and started seeing motorcycle accidents where the helmet came off the rider before any helmet impact at all. Sometimes they lucked out with no head contact. But many times they did not. They thought they had protection. But their helmet was too big. A bad time to find out.
It's easy to tell if your helmet fits or not. Simply put it on, reach over the top of your head with both hands and grab the lower edge of the back of your helmet and start to pull up. If you can pull it off or even come close. Your helmet is too big and it may well abandon you when you need it most. There are other indications like if you move your head back and forth quickly and the helmet moves on your head (you can feel it sliding on your skin). Too big. The helmet will move a little as it pulls your skin on your cheeks and forehead but not slide around.
If you get wind buffeting, or when you turn your head at speed, and your helmet shifts around on your head. Way too big!
That was a quote from a This vs That 'Expert'. Not sure that it necessarily applies. But he thought it did.