Most interesting......
I think it totally depends on the person and surgeon. I, too, have pain in both my legs and lower back. My surgeon placed the battery on my right side slightly above my hip. I have had no problems so far. Actually I'm pretty happy with the placement. (knock on wood!!) It does not affect any of my jeans or dress pants that I wear and it is really easy to get to when I need to program or charge. I sleep mostly on my left side so that worked out well. Although, I have rolled over on my right side a few times. It's still a little tender so I didn't stay that way for long. I am right handed but am a bit ambidextrous so I don't have a problem with the controller.
I think it's something that should certainly be discussed with your surgeon about the pros and cons of the placement. I know one of the questions my surgeon asked was if I would have a problem with where the scar was......referring if I wanted to wear a bikini or something. I figured I already had a scar from a c-section.....I was going to have one on my back from the leads....why not have another on my side!! I guess I need one more on the left side to even me out!!! LOL!! Maybe I should settle for a tatoo of a scar on the left side!!! Ha, ha!!