So far through real world tests, see Arista 400P photos here, we have established that the 400 film behaves a lot like Tri-X, producing very usable results in D76H and Diafine. I am planning to test it in Rodinal, but that test will be delayed by a week's worth of relatives visiting. I have the 100 on order and plan to repeat the tests with it. If somebody wants to break out a densitometer that is fine. I am more interested in real world tests because I usually do not photograph with a densitometer. I am planning to switch to the 400 speed version as my main B&W film because it produces images that suit my vision of what I want in my photos. That is the most important test to me.
Yes, I would love to see these same films in 120 and 4x5. So far, I know I would buy the 400.
PS - I promise not to stray too much from the topic of this thread!