Fat Stacks and Aquilar 2 band preamp opinion

Hey!

So I've got a custom made bass with DC sized 20+ year old Bartolini pickups. I swapped out the also 20+ year old Bartolini preamp with a bassmods 3 band preamp.
Although I like the preamp, I'm still not getting the tone I am envisioning. I still find the bass too mellow for my hard rock taste. And am looking for a more aggressive sound.

First step is stings, I've got a set of EB Cobalts on the way, so we'll see what that does.

Next step is the pups.
The Fat Stacks are my first choice so far. I've listened to some demos and like what I hear.
But looking for first hand opinions, specifically for hard rock to metal music.

Last step would be a preamp. I've herad the Aguilar OBP 3 band can work for more aggressive sound. But really, I'm too big a knob tweaker (wait, wut?), so I'd really rather just have a 2 band on the bass, and tweak the amp as needed.
What's peoples experience of the OBP-3 vs the OBP-2?

Too many questions!!

Thanks!