5D: Interchangeable focusing screen, what does this mean exactly?

One of the features of the 5D is that it has an interchangeable focusing screen. From Canon's 5D whitepaper (PDF):

Now how does this work exactly, especiall with the Ee-S screen which is "intended for lenses f/2.8 or faster"? Does it mean that the AF will also be more accurate if you use the Ee-S focusing screen? And what happens if you have a lens slower than f/2.8, can you still use the Ee-S screen?

How easy or hard is it to change focusing screens, is it something that you can pop out and in just as easy as changing lenses?

How useful is it to be able to change focusing screens?

IF it works like on the 1 series camera it will take about 3-5 minutes to change the focus screen. The actual change takes less then a minute, but since you don't want to damage them it takes a bit more effort to handle the screens. I can do a lens in about 10-15 seconds (30 seconds with caps)

I would suspect that the Ee-S screen will cause a touch more hunting for >f2.8 lenses.

I have no clue what using the Ee-S screen will do for auto focus as it is designed for manual, although using the split prism does not seem to have affected my 1 series auto focus.

And the advantage of being able to change screens is that you can use the best screen for the job. For some jobs the grid is the screen you need. If doing a lot of manual focus work (macro and tilt-shift come to mind) then having a better manual focus screen is better. But for standard quick auto-focus work the standard screen will probably be best.

For the 1 series there are 9 screens to choose from (more if you add 3rd party products)

All I know is I hate the standard focus screen on my D60 and 10D and prefer the Ec-B screen on my 1DsMkII to the standard screen. It makes it so much easier to manually focus and does not seem to significantly affect auto-focus.

I started thinking about this too when i saw it.

One thing i can safely say is that the different screens won't affect AF at all .
This is because autofocussing is all done in the bottom of the camera from light reflected down there and is totally seperate from the focus screen.

Obviously the Ee-S screen shows changes to focus more dramatically but it is probably also darker.If so this wouldn't be a problem though because it's intended for fast lenses anyway.

Ok, thanks. So probably it doesn't matter for AF, but it does matter for metering (that's why you have to set C.Fn.-00 to the screen you're using). And the reason why it's intended for f/2.8 or faster lenses is that it makes the viewfinder darker.

I just checked out the prices of focusing screens at B&H, they're not really expensive ($27 - $34), so it's not something you wouldn't buy just to try it out...

Does the default focus screen have prisms/microprisms ? Any one of the replacements ?

I find it great, even when using AF lens !

Iit's true a different screen make default metering off on my 350D; I now know in which direction for each lens of my lens etc, but it still requires careful inspection of the histograms to make sure