What is the best position for the saddle? Is mid-way on the rails too far forward? I'm been contemplating my saddle placement/stem length for a long time. I love my bike but feel I might be able to get more power out of it if I were seated a little further back.

Currently, I have a zero setback seatpost, and a 70mm stem.

I'm 5'3"-ish with a slightly longer torso and a top tube of 510.

I'm not a very aggressive rider and desire to enjoy my rides but the saddle position/bike fit issues keep recurring in my mind!