I'm more interested in the drop than the full size. I really don't want it to whistle though and I think they could do to make the acf a bit more resistance - looks like it would move on its own freely.
That air flow ring seems to be the number one complaint about the lemo, but I think it actually works pretty well. I do have mine all the way open, but I have used it at a few different settings and it seemed to stay in place fine. When I adjust mine, I don't tilt it upside down, I lift it over my head, look up at it and adjust it that way, maybe doing it this way is more efficient for whatever reason.
I don't get any whistling with my lemo and I think this has to do with how the air flow control is set up. Unlike the air flow controls on most other units, which open/close the airholes on the outside, the lemo is actually opening/closing the holes of the center post pin. I think this design makes it less prone to whistling and in my opinion, give you a wider range of air flow settings. You can have the air flow wide open on a device with the outside control, but if the corresponding holes in the center pin are smaller that that "wide open" hole on the outside, the air flow will still be somewhat restricted.