Digital BW, The Print

Has anyone compared these two devices in terms of accuracy (specifically luminance data)? A printing house I'm considering going with for large prints made two test prints for me that included a 21-step grayscale image. Neither was close to linear, according to my Spyder3 Print Spectro. When I pointed this out, they claimed my device wasn't accurate and that their profiles (made using the Eye One Pro) are linear. But they won't measure my test strips with their Eye One Pro or share their linearizing data. Obviously, I'm skeptical, but I'm curious if there's data available on how these devices compare.

Mark