I was reading the very interesting website you posted duanew, particularly "Biomechanics of Lethal Force Encounters - Officer Movements". It's very similar to some of the research I've read in human computer interaction, particularly to do with learned user interfaces. This website is a treasure trove.
Anyway, it has this relevant finding:
"It is significant however that one of the fastest draws and the slowest draws occurred from a level 3 duty holster and were directly linked to the amount of practice the officer had with that holster ... the greatest factor in the speed of the draw is the amount of time the officer spends practicing with that holster."
It appears that from a biomechanical perspective, practice in a non-stressful environment will result in improvement which I think they imply can be used in a stressful environment (unless the conclusions drawn in the article are purely academic).
""A Survey of the Research on Human Factors Related to Lethal Force Encounters: Implications for Law Enforcement Training, Tactics, and Testimony" is also an interesting read, particularly the sections on Response Times and Implications for Training and Tactics, which will probably affect my own training in future if I spend time on self defence.
Quoting: "Realistic, complex scenario-based training that includes the full range of physical and mental tasks an officer is required to perform in a deadly confrontation, up to and including the recall and reporting of critical scenario details, is essential to improving an officer’s performance and resiliency following such encounters. Repetition, then, further increases motor memory and mental processing as well as provides for positive practice of these critical perishable skills. Realistic training, 144 Law Enforcement Executive Forum • 2008 • 8(4) which includes the unexpected, also reduces an officer’s tendency to overanticipate and preemptively react with a pre-programmed response when a novel response may be more appropriate, thereby enhancing mental, interpersonal, and physical adaptability (U.S. Army Research Institute for the Behavioral and Social Sciences, 2005)."
It appears that there may be some benefit to reality based scenarios and removing conditioned responses, although reaction times suffer. I guess the question is, for a civilian, are reaction times more important than novel thought?
However they do point out that "Repetition increases motor memory, mental processing, and intuitive decision making under stress.", indicating that training for motor memory is beneficial under stress.
Thanks for the website duanew, it's definitely going in my self defence reading list.