Given that this whole discussion started over 2 and a half years (and 90+ Talkbass pages) ago, I'm a little late to the party, but I can now stand up and admit that I am a Zoom B3 convert. My journey started over a year ago when I started playing regularly in local clubs that required a bit beefier of a rock rig than my original combos. On the advice of a fellow bass-playing friend, who's bass tone I REALLY liked, I began acquiring new gear. It started with moving from a combo amp to a separate preamp/power amp configuration driving standalone full-range speakers.
The power amp was a great local Craigslist find - a QSC GX5 dual-channel PA amp (500 watts/channel). I wanted either a QSC or Crown amp as I've had some experience with them in PA's and they provide excellent clean full-range power.
Based on a lot of reading on other Talkbass pages, I took a shot at trying fEARful speakers and found a few for sale here. My rock rig's tone is now accurately (and loudly) recreated by 2 fEARful cabs (a 15/6 and a 15sub).
Finding the right pre-amp proved to be more problematic. I tried a few BBE pre-amps (BMax and 383) a Peavey Maxbass (all were good, but didn't give me everything I wanted) before settling on an Ashdown ABM RPM unit (my combos were Ashdowns - which I also really liked) - which along with a 7-band EQ, gave me tube pre-amp grit and and a subharmonic generator.
Still, I found that dialing in "my sound" was a bit difficult, especially when switching basses. Going back to the discussion I originally had with my bass-playing friend, I noticed his other recommendation (aside from a PA amplifier and full-range bass speakers) was the use of a Zoom B3 (which he told me he mainly used with the SVT patch). I was a little skeptical about simulation, but figured if Geddy Lee can use it to get a lot of his live sound these days (aside - just saw them on the current tour in Boston - first and possibly last Rush show), it was worth a shot. So, a few months back, I started searching Talkbass for posts on the B3 and of course came across this thread - the prospect of using the B3 as my preamp definitely looked promising, and when I finally snagged one of Ebay, I set it up per all of CharlieC's initial recommendations, and tried out a number of amp sims and effects. After setting up a few custom patches, I tried it out at a recent gig, and made myself (and probably everyone in the room) a believer!
At the moment, I'm finding a lot of joy out of the SVT sim as well (switching in the ParaEQ for certain songs), although I'm very interested in exploring some of the other sims (especially the GKrueger and B-Man amps, plus the BassDrive, and BassBB preamps). I'm also looking forward to being able to throw in the occasional distortion, wah-wah, sub-octave, or envelope filtering on a few songs, and playing around with other effects. Having a built-in tuner that mutes the signal to the amp, a computer interface, headphone jack, and XLR out for the PA (among other features that I might not ever use)...well that's just a bonus.
Thanks to all who have contributed to this thread (especially CharlieC who got it all started and did so much of the groundwork for the rest of us) - maybe I'll have some future experiences to share later (or patch ideas). Rock on!
John