Outdoor in bright light you can hand-hold using the lowest ISO for good resolution with a larger f-stop for better details.

What exactly is the difference between the previous F770 & F800? According to Fuji you're supposed to get better results in low-light. You can bypass the aperture & shutter by using M when necessary. But unfortunately Fuji did not put in MF so in the worst case scenario you can switch to manual focus and still get something when the camera won't do it for you.

The resolution is the same for both models with a few added settings on the menu. The 1 setting added for F800 is multi-exposure. You can exposed images on top of each other. However this works only in fully automatic mode so you don't have room to fiddle around with the settings.