I contacted Schuberth about the battery life question. Their response is it should last 10-12 hours of actual talk time. That sounds about in line with the G-4.
On the issue of range though. It seems they could mount a external antenna on the side of the helmet in such a way that it blends in with the helmet and is hardly noticeable unless you are looking closely at it. Just match the antenna covering based on the color of the helmet and have it flexible enough to follow the curves of the helmet. Maybe I am missing something here but it doesn't sound like it should be very difficult to do.