hello----the cost/benefit becomes a real consideration, but if you are thinking of additional enhancement to the dasc, check out
www.techniquetuning.com nick is the guru there and he can assist you with his kits, which are designed specifically for the m44 with dasc. i got the stage 2 upgrade, and it is wonderful. the reliability of the dasc and the tuning upgrade are very good and driveability is excellent---occasionally you may get a bit of idle flutter, but not a concern. you can probably investigate a few other threads on this board to find comments from other folks who have this installed. some have changed the pulley size to generate more boost, and horsepower. mine was recommended and installed by a shop that builds bmw race cars, and they had very positive experience with others they had installed. mine was dynoed with 190 hp at the rear wheels, which equates to about 225-230 at the engine, with 175fp of torque. my car had about 120k miles on it when modified, with 130k now, and running strong.