For filming I prefer eCCR. Especially in shallow water it gives more security. A normal filming scenario for example ......red see, deep 18 meter, visibility more than 25 meter. You see a big shark, manta ore turtle 20 meter from you. There is a little current, not to much, but with the rebreather, the video-light, the video-camera you have just to work a bit harder to come closer. You are at 10 meters from this nice shoot, you start the video-light, correct the angle of them, because before you made a macro shoot to a small fish, you correct the video-camera settings, focus, w-balance.... and start it. You come closer 7 meter, but the fish or turtle moves from 20 to 15, 12, 10, you are concentrated to the viewfinder and the buoyancy .... only a bit closer for the perfect shoot, olny some more seconds than....uuuuuups forgot to check the PPO2 on the mCCR
. That's only a example, but I'm sure eCCR is better for the video freaks. mCCR works fine too, with a hud and for deep wracks, caves - filming.
Friendly Oswald