Sorry for bringing up this old thread, but I suppose this information is relevant and useful.
Based on my recent experimentation with various MIA Cirrus basses, I gathered this: there were two versions of VFL pickups, early unmarked version which was used since beginning of production and Korean (?) version, marked with "g & b co" sticker underneath, which appeared later on (no later than 2005). Physically they are similar, but internal electronics differ sharply - early pickups saturate and distort quicker and thus sound more compressed. Later version pickups have more clear, rich and punchy sound and react to the blend pot almost as if it were a three-position switch.
But the most glaring distinction is power drain - earlier versions draw only about 0,5 mA each, while later draw 5+ mA! Combined with a preamp, they use about 12 mA! Therefore some Cirri are quite conventional active basses with common battery life expectations, and some are better sounding, voracious eaters.