Difference between regular and eccentric trailing arm bushings

[validius]

I see that ECS offers an eccentric trailing arm busing (PN: 33329058822) which is listed on the same page in RealOEM as the non-eccentric bushing (PN: 33329061945). The price difference is rather large ( $45 vs $12 ) for Febi. I was planning on just buying the OEM BMW ones. Any reason i should consider the eccentric ones?

[NC325iC]

the eccentric ones are used to provide some correction to rear suspension geometry. I am not sure if the eccentric ones are adjustable after they have been installed or not, but if so it would allow someone to improve the rear alignment of your car. could give you better driving characteristics and improved tire wear. Depends on if its worth it to you for some additional (though limited) adjustability.