CM,
Yes,it comes with lower back pain, I imagine it is the muscles trying to adjust to the pelvic readjusting.
Your right, it is amazing. I just need to keep off the weight I have lost and get down to about 180 to 175. One good thing about loosing weight, my old bras that fit me pre NBE at 235 lbs, which I out grew, now fit again at 205, except the band is a bit looser, even on the tightest setting.