Have you kept both the BB and BV?
I think @Erithon might have both as well
I did own both and I ended selling the Bass Blaster. I prefer the Black Vehicle for four reasons:
1. The Blend Control. I value being able to mix in clean, dry signal with overdriven harmonics.
2. I thought it sounded better with other pedals. I think the Bass Blaster sounds better on its own, but when combined with other effects or in a mix I prefer the Black Vehicle.
3. The boost. It's quite useful when you want to make part of a song (instrumental, bridge, final chorus, etc.) sound a little different.
4. The flexibility. The controls allow for more tone shaping, and the pre-/post-boost is a very cool feature.
All that said, I still thought the BB-2 sounded excellent. In fact, as I say above, I preferred its sound when placed in the loop of a Damnation Audio Loop Blender and those were the only two pedals between my bass and amp. It has some other things going for it too: smaller footprint and cool orange color.
Both of the BB-2 and BV-1V excel at low gain overdrive. That's actually how I use my Black Vehicle: subtle breakup that I can manipulate with my right hand. Sometimes I have another drive after the BV-1V as a third gain stage (the BV-1V's boost being my second gain stage). They do sound different, however. The Bass Blaster is sounds thicker and warmer; the Black Vehicle is more articulate and also more responsive to right hand pressure at very low gain. There isn't low-end loss on either, but because of the lack of blend and the harmonic frequencies it emphasizes, the BB's low-end isn't as punchy as the BV-1V's. It's more mixed in with the overtones. Think presence over projection.
For what it's worth, I've owned and/or played scores of drive pedals and the Black Vehicle remains my favorite non-tube drive pedal. It's responsive, versatile, and, most importantly, I love its voice. (I do wish the input, output, and power jacks were all on the same side of the enclosure. The current design is frustratingly inefficient in that regard.) I've never experienced the sort of power issues @Snaxster has. I wrote a pretty extensive comparison with the Origin Effects DCX Bass some months ago: I've linked it
here in case anyone reading this thread finds it helpful.