Thank you all for the input. Based on the feedback, I'm going to go with a full face and will buy whichever one feels most comfortable.
I thank everyone for all of the useful info on this. The results came out differently than I would have thought. I've always used open face so far (tried closed face and too hot and too visually restrictive). But I thought that now that I was upping the speed in the McLaren, closed face plus HANS would be important. Thanks to various input on airbags (yeah, didn't think of that), HANS not working with three point belts, and the use of open face by some full-on professional drivers, I think I'm going to stay open face for now.Open cockpit racing: Absolutely full face
Closed cockpit racing: Your choice, a little more protection with full face, but a lot more visibility/comfort/breathability with open face. For the other comment, lots of professional drivers use open face helmets. Rally driving, which probably has the most spectacular crashes, open faced is is the norm. Most of the drivers running Pike's Peak, were a slip up can be a fall off a cliff, use open faced helmets, including Randy Pobst. So to say all professionals use full face in a closed cockpit is a bit of a stretch. Even Nascar, which promotes full face, some still wear open faced.