With the powerful Pawnee the p-factor under full power is quite prominent and requires a lot of rudder input to keep the ball centered. This takes quite a toll out of the pilot over the whole day. The glider can help by off-setting its flight path on the rope off center to the left.
Our 180hp Cessna 152 requires a lot of elevator pull to keep the climb. The glider can help by assuming the low tow position below the wake and pulling the tail down a little bit by doing so.
Both techniques help reducing the tow pilots load and make the flights more pleasant. It makes a big difference over the length of a day.