I have not measured the SRAM able pull myself, but the 3mm value is what SRAM videos claim the cable pull to be. Zinn came up with 27.9 for the total SRAM total cable pull, and 27 for Campy, which makes me think that his measuring technique was not accurate. Campy is absolutely not 27mm, it's 25.9mm.

I measured the Campy cable pulls myself, using the most accurate method I could, without using a precision dial indicator setup. I use a machinist's rule with .01 inch increments. I've measured the pulls several times always come up with the same values.