I'd say a F5/1V/1D/D3 class body with a sealed lens (Canon L or new Nikon ones with gaskets) is more water resistant than a Hassy. However a F5 with a regular AFD lens is probably just as good, your main issue is getting water in the lens, if you wipe it before using the aperture/shutter rings you'll be ok and make sure you don't transfer water in focusing (water on extended barrel carried inside when focusing). Obviously if you're not using a prism, leaving the WLF chimney open in the rain is not very wise.
I've used my 501 in moderate (i.e. I could stay out with waterproofs without thinking "this is crap") rain with no issues, just made sure to wipe it every now and then to avoid getting standing water on it.
Overall, I'm more comfortable using the hassy in the rain as if water gets in it should still work while an electronic camera will just die. How you get the water out and avoid rust is another issue!