I have a 300 in a Range Rover Classic which is pretty close to the D1. With the auto it was pretty anemic, but that could be because the motor was tuned poorly. After the manual swap and re-timing, the truck went fine. Not fast off the line (need the EVO kit for that), but would do 75 to 80 on the highway and cruise like that all day so long as no slow traffic joined in front, no hills were involved and the wind stayed tail-wards.
Make no mistake this is not a fast combination and anyone who uses anything other than a 110 tdi as a daily driver will be pretty shocked by the performance. But there are tricks like the EVO kit that help tremendously with drivability. No rocketship, but good mileage, great torque and that fantastic tdi sound make it all worth it.
cheers