I have the "X series" version of this set. The 40DCX are an even hotter humbucker than the 40DC and nearly no background sound. These pickups are a marvel of technology. I'm running my set, which are set to run at 18v, at only 9v. At 9v, it sounds like the most powerful, thickets bass ever.
VERY versatile. With the EMG BQC preamp system, I can make the pickups sound bright and plinky like a single coil, or muddy, warm, and thick like a mudbucker. I have my settings so that the back pickup is slightly high and the front pickup is low and deep. It's perfect. It sounds like the best Precision Pickup in the world; Crisp and Powerful.
Buying these pickups took away my guitar lust / GAS. I don't want another bass unless it has 2x 40DCX in them and a BQC system attached.