Hi Jeff,
There is a speed control on forward and reverse both...so you can adjust the speed separately for advance and retard. You can have it slam instantly or take forever.
Lots of guys run it with a fairly slow advance rate to bring the timing in over a second or two at the beginning of a run. Then they have retard setup rapid so when they see the 1000' mark, they push a steering wheel button to have it slam back at the top end.
Spud