Per other thread we installed microsoft .net Framework 4.0 on our XP pro server and workstations. (We had 3.5 previously as seen on control panel/add or remove programs).
After this update, AC is greased lightning just like V5.0.
My staff noticed too that it was faster. They noticed especially on imported items. Their (and mine) med list screen - left for past ones and right one for script writer-- was faster too- staff do not need to check interactions. So their interaction cheker is turned off in their settings. (Not for me as MU is based on ME to attest to CMS).
So in my mind I believe it was this issue that was the reason AC v 6 0 9 was slow. (Mind that sometimes mind can play tricks or 2).
http://amazingcharts.com/ub/ubbthreads.php/topics/33295/Just_upgraded_Write_Scripts_pr#Post33295
