Hmm. That might be a start, but I'm thinking more of something like this:
1. bump that grabs the front of the trigger guard. This would allow the gun to be free once the bump is cleared, for minimum movement before release.
2. Screw to set retention strength on above.
3. Rearward cant, about 15 degrees. Best compromise for waist and surrender starts.
4. No gripping on the cylinder. Once the bump is cleared, I want the thing to jump out of the holster.
5. Very small shelf to prevent the barrel from tipping backwards if I hit the grip too hard. Perfect would be for the barrel to clear at the same distance of draw as the bump.
6. Minimal holster material under and behind trigger guard. I want to get my hand on the grip as fully as possible before starting the draw.
7. Slight outward cant, a la the Bladetech DOH.
Summary would be a clean grip presentation, somewhere about 4cm out from my front pocket, with a slight rear cant, that releases in 3/4" or so. A swinging lock would be nice, something that would swing behind the trigger guard for between stages. And remember, I'm a lefty. And of course we would have to arrive at a price.