As far as elevator goes John it is always (particulair in combat I can imagine) to have the trim set fairly good, it takes a whole lot of load of your arm.
Like HT described above, if you trim a plane half negative (for high speed, nose down) the control stick in the cockpit will actually move half way forward, now if you enter a turnfight at this trim setting you will have to pull the stick alot further back then if you trim the plane possitive and let the trim do the "pulling" for you.
Not sure how to explain it good, it becomes very apparent in R/L flying.
Had I been in a combat I would proarly have tried to change elevator trimming as often as I could.