Okay, I'll ask for some of that good xDrive liquid tomorrow and replace it too.
So I get your argument about weight reduction but when it comes to critical parts that directly affect the reliability and resilience of the car, that thought is just unpersuasive coming from BMW's part. Yes, weight has a direct effect on a variety of factors such as MPG, etc but a metal propeller and a metal gear for the actuator would have been more beneficial than detrimental... I suppose you are right about whether is it preferable for the average owner to have a metal impeller that corrodes down to nothing because the coolant didn't get changed often enough, or a plastic one that fails through old age. But I think getting a coolant change is far easier and cheaper than getting the whole water pump replaced.
Anyways, you've been great mate and I thank you for your time. I will be getting the parts and doing the swap hopefully soon... I got to finish these finals first.