If i manual shift down with my PDK base Boxter, engine will break. But you have to shift down two or three times going above 5000-6000 rev. I use that for slowing down when coming to speed limit or crusiing to trafic lights, as i will do with a manual gearbox.
With low REVs i can not feel an significant enginebreak.
With low REVs i can not feel an significant enginebreak.