| I've owned the BDDI, PDDI (and Behringer copy) at one time, and I just got a VT Bass. I've only owned it a week or two, but so far I like it. To be honest, it's nothing I use all the time, like a preamp. I used to use my BDDI's for pick playing as I felt it took the edge off a little and removed some of the harsh mids. However, these days I'm basically bass-amp regardless of pick or fingers.
My VT Bass is basically my light dirt/overdrive/grit box for the moment as it replaced my Fulltone Bassdrive. I've looked forever for something for that purpose that I didn't completely hate, so I'll give the VT Bass a try. It has plenty of tones and is quite versatile, actually. I've said this in other posts, but it's a touch more transparent (especially in the mids) than the BDDI's. The mid control actually makes a difference, but the VT bass has the similar mid-scoop characteristics of the BDDI, likely due to the cab-modeling.
Like I said, it's what I'll use right now but my mind changes much....
Hope that helps,
Lyle | 
