(I'm not sure about Bill's settings but)...
In my 1197...I have generally found that the 455 will be brighter than the 800 "at the same sensitivity setting"...which sometimes can give the image the conception that the "brighter" 455 setting looks better...
When I raise the 800 sensitivity setting to get the same image "Brightness" .. The 800 is noticably crisper...
This is reason again to constantly adjust the HB Sensitivity setting to get the best eye appealing image at any given point or circumstance...
Rickie