Like DaSpy, I have both the Baby and the Platinum. I use the Platinum 90% of the time, because I know how to get it through metal detectors.
The Baby Box is really just a battery box supplying the voltage to run the Schoeps. Initially, I disliked it due to the sound, but quite frankly in some venues, metal detectors, wands, empty pockets and pat downs (yep, there are few really aggressive venues), it came it useful. I got over the sound, and developed a plug in setting to boost the frequencies that needed, actually a curve of sorts, and it its hard to tell the difference these days. Like DaSpy, I use "Mike In" on my recorder, not "Line In." You'll need a special set of cords for the Baby Box, the two are not interchangable with the NBox.
I'll always take both to every show, and decide after checking out the security line which preamp to use. Like I said, the Platinum is still my go-to preamp.
But if you are unskilled or paranoid about security checks, then I suggest the Baby NBox.