A great linestage/preamp "makes" a great system

I've evolved a very nice and synergistic 2 channel music system over the past decade (posted). The learning curve has been very steep at times, but the result has been worth the ride. The one component I've found the most elusive to get "right" is the linestage/preamp. I've owned resistor-based attenuators (EVS and Endler), passive TVCs (Django and amorphous core Promethius), Musical Design MP-1b and custom 2 box "balls out" (Black Gates/tantalum resistors/Schottky)solid state, fully tweaked Atma-Sphere MP-3, and Blue Circle 3000 GZPZ tubed units - all of which had virtues, but none possessing the full package. I understand where the passive crowd is coming from. That nth degree of transparency is very hard to get from actives. Likewise, the liquidity/body/"humanness" of great actives adds so much to my musical enjoyment. My new Audio Note L3 Kits "2 box" Custom build from Bill Baker of Bella Extreme has finally gotten me the best attributes of both passive and active designs I've used.

I'm wondering if any of you, like me, have been on the journey a while and have found the linestage/preamp to be the trickiest to get "right" in your system. For me a truly outstanding one is the centerpiece of my system.