When I started playing in church 3 yrs ago, I learned to play through the SansAmp BDDI because that's what was supplied by the church. Not too bad as a basic tube emulator for adding warmth but not a whole lot of tonal options due to relatively limited range of controls. Besides, it is very scooped by default - too much bass and not enough mids.
The VT Bass DI has the same tube emulation circuitry as the SA BDDI, but the default EQ curve is a lot flatter with a dedicated mid control and a wider range of tone-shaping capabilities, including better overdrive.
I kind of figured it would be simpler and less work, not to mention more cost-effective, to be fiddling around with knobs on this thing in an effort to find MY tone than swapping out pickups and pots on the basses themselves. Both of my basses are still 100% stock, except for the pickguard on my J, which is purely cosmetic.
Having a brand new set of the 9050CL is giving me an excuse to experiment a bit with my VT Bass settings to see what kind of tone I can cook up.