I have an '07 Forester with the Turbo.
While going downhill using the cruise control, the engine pulses. I can feel it as a retard/acceleration.
It seems when going downhill, the engine backs off and the car coasts, the car slows down and the engine then comes back on for an instant and when the car speed exceeds the set point, it slows down, Thus the pulsing.
This happens on the hills of Connecticut, where they are slopping gentle downward and the speeds are in the 65 to 75 range.
On level and uphill, no problem at all. Neither my '96 Outback nor my '03 Outback (H3) had this problem.
Al