I agree, the biggest jerk is when you go drive to reverse. I have had my trans looked at and there is nothing there. I also notice that after I bring it in, it tends to go away for a bit.
Since we are talking about transmissions, does your car need to heat up 10 - 15 minutes on real cold days. This morning it happened for just the second time, both times it was real cold, under 10 degrees.