The battery box is not a pre-amp, so you may still need to use "mic-in." The SONY RH1 has a very good front end, line-in, mic-in lo, and mic-in hi so you have three flavors. Point: you can always make it louder. You cannot get the clipping out once it is there. You can play with it, smoothing the edges of the clip, but it will always be clipping.
I cannot vouch for the Microtrack, but I have a little RH1 and think it is sweet.