You can turn off the backlight on the screen, that takes battery life up to 75 minutes, or so, and is OK if ambient light is good (hold the menu button down for 2 seconds). Of course, you can't change a darn thing when you are actually recording
My experience with the 10x zoom on the HD1a is that it is real tricky to hold the camera steady at that level of zoom.
It would be nice if you didn't lose an f-stop of aperture every time you used the 5x zoom on the C6, though. The C40, for example, maintains pretty constant aperture over its zoom range
F 3.5 (W) – F 3.7 (T)
OTOH, there is a built-in 'lens hood' on the C6:-)