Since Anton is in the rental business, his needs and wants are different from an End User. I understand his frustration. I'm sure his customers ask for crazy stuff, (like shooting sixty frames in a row, wide open on Continuous, with the mirror up?). I've been wondering for hours exactly how that could be used in the real world. But like he says, If they advertise it, it ought to perform that same way.
The thing for me is simply how it feels in my hands, in real use. I could care less about sixty frames in a row, but what I do care about is TWO frames in a row, if I was shooting people.
I remember owning the P30 and P45, and then one day, I got a P21+. The P21+ was a massive difference, mentally, for me. For the first time, I had a MF camera in my hands that actually FELT like a 35mm camera, in terms of responsiveness and recycle. When I'd shoot a frame with the P30 or P45, my reaction would be: "Shoot, OK, wait, wait, wait, wait, OK go". But when I shot the P21+, the internal reaction was: "Shoot, recycle, GO; shoot, recycle, GO". Almost immediate it seemed.
If they get a full frame back that feels like a P21+, response-wise, they'll have a real winner. Who knows, they might already have it. Of course, I'm talking about shooting people here, and following expressions. It comes down to the question: "Will I miss the expression I see (and want)". I rarely missed it with the P21+. I only sold it due to it being cropped-frame, and using it on a Contax 645, which had a very dark viewfinder. Small and dark equals Not Good. If you can't see it, you can't shoot it.
Edit add-on: The other weird thing, related to this thread, is how much the experience of a camera changes (and improves), once you find those silly little Custom Functions. On the H2, I have the User Button set for AutoFocus, and I have that top AE Button set to raise the mirror. Once I discovered these two little features, it was like getting a whole new camera handed to me. Those two functions completely transform the USE of the camera, day in and day out. I'm almost amazed that you can't export a set of Custom Functions, so that you could discover these hidden functions that are so helpful. Amazed you can't export them and trade them like baseball cards -- get the Mickey Mantle set, or the Richard Avedon set, or the Gregory Crewdson set.