> The exception is when >I need to change rapidly from flash to non-flash shooting.
Your exception is where I think I have been dissapointed in the past. When not using flash indoors I am fairly happy with images up to iso 6400 and sometimes even higher, but when I want flash on I would rather not have such high iso's. Now instead of just popping up my flash and shooting, I will use a user defined setting with auto iso on for non-flash work indoors and an aperture priority setting or manual for flash work where iso is set manually. It is quick to turn the dial and no big deal.
"Cameras and lenses are simply tools to place our unique vision on film. Concentrate on equipment and you'll take technically good photographs. Concentrate on seeing the light's magic colors and your images will stir the soul." Jack Dykinga