Opinions on Welborne Labs Zephyr passive pre

I've had one for several years and am very pleased with it. The remote works well from about 25-30 ft. and has volume, balance, mute, power, and input controls. My Zephyr was factory built and has one set RCA inputs and one set of RCA outputs. I've A/B'd it with a Bottlehead Extended Foreply III active tube pre and it was hard to determine a difference between the two! The Zephyr was a bit more defined/precise but the Foreplay had a somewhat deeper soundstage and could achieve a higher gain. Speaks very well for the Bottlehead.

My system:
*Sony SCD-777ES SACD/CD player-modified/upgraded by R. Kern
*Welborne Zephyr passive pre
*Welborne Laurel II Ultimate 300B SET monoblocks w/ WE 300B's
*Klipsch Cornerhorns-1970s vintage w/ alnico drivers
*Audioquest cables
*Monster HTS 3600 Mk. II power center

I am thinking of trying one as well, so I'd also like to hear opinions.