That's expensive as hell for delrin! I just talked to my father earlier (after my last post), to get a comparison on what they used to pay for delrin (again, it's been about 5 years ago since he retired). They paid about 3/4ths of the price for delrin that they did for aluminum. Maybe being a Cisco company they bought in large enough quantities that it was cheaper. I'm not sure on that. All I know is that any time they would prototype a part, they would make the prototype typically in the cheaper delrin to test fit, before finalizing a design and having it made from aluminum. I would even get to go in the shop with him sometimes and practice milling with it. And delrin is a lot more abrasive resistant than aluminum, that is why it's used for seals, joints, etc. Lots of automotive racing bushings and mounts are made from it because of this reason. It's not very shock absorbent however, as anyone who has put delrin bushings and transmission/engine mounts in an car can tell you (I have racing delrin engine and transmission mounts installed on my MazdaSpeed 6, and the entire car vibrates at idle because of this---a known effect before you do it, but the increased rigidity helps with torque transfer to the ground). But if you look at it's qualities/properties, it's listed as not very impact resistant, especially when thin.