I have middleburns (not fitted yet) with the dual 4-arm spider. Reason: UNO chainring is 50 quid a pop. Bash guard (butchered 32T, would rather not have 4 arms sticking out) on the outer ring, 26t on the inner. As snoops said, lifetime warranty is pretty assuring in terms of wear and durability.
I have middleburns (not fitted yet) with the dual 4-arm spider. Reason: UNO chainring is 50 quid a pop. Bash guard (butchered 32T, would rather not have 4 arms sticking out) on the outer ring, 26t on the inner. As snoops said, lifetime warranty is pretty assuring in terms of wear and durability.