Thanks 26 Inf. I use the thumb of the support hand to eject spent brass similar to the technique JM demonstrated and use the shooting hand to insert a Comp III speed loader in competition. I do not teach this technique in a class, because I feel there is more room for error than using the strong hand technique.
I teach students to:
1) Hold the revolver in the strong hand and apply pressure to the cylinder release with the right thumb on a S&W or left thumb on a Colt.
2) Push the cylinder open with the two middle fingers of the support hand and trigger finger while tilting the muzzle up to approx. 12 O'clock with the butt facing the support side shoulder.
3) Strike the end of the ejector rod with the meaty area on the support hand where the knife edge and palm meet. The knife edge of the left hand slides alongside the barrel and the trigger finger maintains pressure on the cylinder while doing this.
4) Shift the revolver to the support hand with the two middle fingers pushed through the frame and holding the cylinder open and lowering it to belt level while reaching for a speed loader or speed strip with the strong hand. The muzzle is tilted down between 4 and 6 O'clock,
5) Rotate the cylinder slightly with the support hand thumb and middle fingers while the strong hand guides the speed loader or speed strip to the cylinder. (There are different techniques for manipulating the loading device depending on type, HKS or Safariland speed loader or Speed Strip.)
6) Close the cylinder with the support hand thumb while the strong hand acquires a firing grip.
This takes more time, but as you pointed out the primary concern is reliable ejection and reloading.
I've played with moon clips on a borrowed revolver and could cut my reload time down considerably if the clips were positioned on a belt carrier like JM was wearing in the video. Stored in a pocket, I don't have a significant advantage over a good speed loader and I am not going to wear a rig like JM was wearing for concealed carry.
For anyone considering a moon clip conversion on their revolver, Tom Kilhoffer does nice work. http://www.tkcustom.com/content/contact_us.asp