Are e thirteens worth the money?

bikerboywill
bikerboywill Posts: 23
edited August 2007 in MTB general
I am just about to buy a new single ring chain device for my bike. i have got 2 in mind a blackspire NS-1 C4 or an e thirteen srs. i like the look of the blackspire more and i think it would work better but is it worth the extra money for the e thirteen :?: