The Line Driver/DI is a solid state preamp (an DI) with a very clean signal path, and no to minimal coloration. The unit will be a "desk top" style (neither a stomp box nor a rack mount), somewhat like the U5 in appearance. Of course, there will likely be SOME way to rackmount it. There are no tone controls. In fact, the first prototype that Jim sent me had on one knob, labelled "More."

It's just the sound of your bass, only with more gain. Of course many products claim to do this, and the proof is in the pudding, so I'll let y'all decide this one for yourselves, but personally, I find the line driver to be extremely uncolored and tremendously full range. It makes other preamps which I thought were full range sound somewhat truncated on both the lows and the highs. It just flat out sounds good (in a very clean, precise way), IME/IMHO.
After my first gigging attempts with the line driver and IP322, though, I spent some time talking with Jim, and he ended up adding a variable high pass filter to the design. With cabs that go as deep and strong as the IP line, I find this to be very useful, especially in rooms with poorly designed stages, or loose fixtures.
So, you'll have a killer, clean, preamp, a phantom power safe, great sounding DI, a volume knob, and a variable high pass filter. At my suggestion, the input impedance has been upped a bit to be more friendly to our upright playing and/or doubling brethren (I think somewhere just above 2 Meg). But nothing, really, beyond this. No tone controls, per se. This will appeal to some, and not to others. But, I gotta tell you, for excellent clean tone, even outside of the context of the IP cabs, the Bergantino line driver is my reference preamp.
Tom.