1d mkiv focusing screen

So I am looking into a new screen and can't decide which would be a better choice. Ec-IV Laser matte or Ec-S super precision matte. I want one that is a little better with manual focus, but I also have the 100-400 so it can't be too dark. What is the biggest difference between the two?

These will still show the ad confirmation, right?

go for the -s screen; it'll let you see focus better when shooting wide open primes. I think it 'should' be ok with the 100-400 since I assume you use that lens mostly outdoors in sunlight?

I believe the ec-iv is the stock screen in the 1d4; cant remember for sure...

Cool thanks.

Yeah the 100-400 is only for outside. I tried using it for a low light zoom, but for some odd reason I couldn't keep the shutter speed up. Go figure.