Long ago, used to have the BMW flip top when they first came out (in Oz). Really liked it because I wore glasses at the time. I NEVER rode with it flipped up, wind pressure on the jaw piece would have pulled my head off.
I did crash test it, but it was a straight high side over the bars into the white van off death, not to fast. Dented the van and the helmet, but it didn't test the integrety of the jaw connectors in any way, so I can't comment on that aspect of it's safety.
On my HD, I have a cheap black full face, not sure on the brand. Needed a helmet when I bought it, and always planned to replace it, just never have. I've looked at open face helmets, but I can't equate value of the vanity and pleasure of an open face to the more legal and safer feeling full face. If I can find a "cool" looking open face that's also legal, I may succumb to temptation this summer, as it's the closest I'd go to letting my wife ride sans-helmet.
On my FJR I have a Shoei RF1000 Diabolic 2 TC-5. This does seem noisy, but I know I should wear ear plugs anyway. It's also a while since I owned a bike this fast.
The wifes bucket of choice is the Shoei RF1000 Nerve TC-1. She loves it.
I can see the attraction of flips, especially if you wear specs, or live somewhere really hot and are stopped in traffic a lot.
I remember having badly bent spec frames from being repeatedly inserted and removed through the face of the helmet, so that would probably decide it for me.
