I've sold or modified every fully passive bass I've had. I definitely know which end of that spectrum I fall on. I do see some people get confused/overwhelmed by the sheer number of knobs without understanding what they do, and they usually just turn them all all the way up, which sounds like hot garbage.
So, yeah, it's a preference thing. Just understand that not everyone will know what to do with all them knobs if they play your bass.
Depending on the preamp, the knobs won't always do the same thing. Some preamps are boost only EQ - they are "flat" with the knobs turned all the way down. Some are boost/cut, with the "flat" position in the middle. Some aren't even EQ in the traditional sense, but low/high pass filters (this is much less common, Wal is the main one that comes to mind but I've seen others as well as aftermarket filter preamps).
I put "flat" in quotes here because even with everything set to the neutral position, the preamp does affect your tone somewhat. Different preamps have a variety of baked-in tones that will always be present if the preamp is active. The Yamaha in my profile pic has a 3 band preamp with boost/cut for bass, mid, and treble frequencies, and it's a pretty transparent preamp (no baked-in EQ) but even with all the knobs centered, the sound when I have the preamp on is clearer and more "hi-fi" while the passive tone is a little more soft and subtle. Neither one is necessarily better, just different. I tend to use the preamp more than not because the clarity helps with the B string definition. I don't do much with the EQ on it because I have an EQ pedal and a SansAmp at the end of my board that do the tone sculpting. I have four other basses, and all of them are passive.
Yeah, after reading through this thread it seems I've erred somewhere. Doesn't seem they're as desirable as their availability would make it seem.
But my main question was answered. There's no difference between an onboard preAmp & one on the pedal board, or on the amp.
Sort of, but bear in mind that the frequencies on your onboard preamp won't necessarily be the same ones as your preamp pedal, so even if they perform the same basic function they won't do exactly the same thing.
I don't agree with the statement that EQ on top of EQ muddies things, it certainly
can if you aren't careful but I have an EQ pedal, a SansAmp, various pedals with their own tone controls - yes, those are also a type of preamp, albeit basic ones - and then the EQ knobs on my amp itself, and they sound just fine. I actually use my EQ pedal to reduce muddiness by cutting just a bit away in the low-mid range and boosting high mids. But that's not a one-size-fits-all solution, depending on your gear you might get entirely different results from doing that. It's very much a use your ears situation, which is daunting at first but with practice gets easier.
Overall I'd say that the use of an onboard preamp is more popular among bassists who like a "modern" sound while passive tends to be preferred by those who want a more traditional, "vintage" sound, but those are broad generalities and there will be exceptions to each. If I were in the market for a bass, I'd probably choose based primarily on what feels good in my hands, since that's much less adjustable than tonal characteristics.