Let your ears decide. I've never done an A/B of the two. I would guess (no empirical reasoning) that the JDI would be quieter since it's a passive DI, but I'd wait for a correct answer to this. The Sadowsky is a cool sounding preamp for the modern slap stuff.
Yeah it is. Considering that i get a DI/preamp boost and the sadowsky sound in a package for $200 (used) is pretty good to me. If it's just a *tad* better than the markbass DI, then i can consider it 'my' JDI! If i ever got serious enough into recording, i'd probably get a REDDI or something, but i'm good for now i guess.
Thanks everyone for your help.