Will origional 5D & 600ex flash be compatable (read poss only sync @ 100th?)

[speirsphoto]

As I have 3x origional 5d bodies which work well for my wedding photog buisness, I need to replace a 580ex flash & would like to use the new 600ex, it will be only used on the hotshoe but I am wondering if 200th flash sync & TTL ext still function as normal. This way when I update to Mk3 ext the flash will be able to be more compatable.

any advise is appreciated. I have looked online but all threads seem to refer to 5dMk2 / 600ex function compatability. Cheers Pete