I had a Warwick in my shop for a setup recently, and was curious about the pickups, since I always read about people changing them.
I was very surprised how nice the bass sounded. With the preamp I got everything from super bright Stanley tone, to thick dub, which is what the owner plays.
This bass had the passive MEC pickups. I don't know what model bass it was... I think it was a Thumb, but it actually made me like Warwicks, despite the baseball bat neck.
I don't think the MEC pickups are based on EMG's. They are two different companies, and MEC is very capable of designing their own stuff, just judging from the MEC preamp I saw. Totally different construction techniques.