Re: Have you actually used Aikido?
There are alot of factors that determine outcomes and skill is relative. Your practice should inform your body in many ways, it depends on how you train and what you train for.
As far as relative goes.... it is relative to your starting position. that is, are you better off than you were in the past? Are your skills better than the other guy in the situation? what is your orientation to the situation and what elements of it can you exploit? which ones are dumb luck?
these things are hard to measure and the only ones you can really quantify are the ones your can control. that is, what base line did you start with....and where are you now.
When you get into discussions on degradation of fine motor skills...again, a relative question. that is, "as compared to what?".
Many "sensei" or "combat instructors" will tell you to not train these things cause you will not be able to use them understress...so the conclusion is "why bother?".
There may be some truth in that to a degree in that we need to develop some foundational skills and understand our "defaults" and learn how to manage those "macro" defaults. However, we must incorporate the technical aspects that are important as well, as Ellis pointed out above.
Technical skills I think depend on the specificity of your particular conditions. If you are a soldier or a swat team member dexterity and muscle memory to load, clear, and reduce stoppage and place well aimed shots are very important and require well trained fine motor skills or you are useless.
As Ellis pointed out, these things don't disappear if you have trained them under the proper conditions and they are ingrained habits.
Problem, IMO, is that most dojos and schools simply do not understand correct methodologies to train this stuff, or they have not developed measures or context (specificity) that their students can gain feedback from.