I had the same bass, and loved the preamp. I've also got the DI pedal, and use it a lot (mostly with Fenders). For me the way to get the best was to use it minimally...maybe 40% on the bass boost and 30% treble. That way you keep the midrange sounding natural and don't have a lot of low end boom. Also remember that your amp settings are being added to this, so keep it fairly "flat" if possible.
I've done a few sessions with just the pedal, and it sounded better (to me) than some very pricey DI units. Good job we all hear things differently.....