First, ask yourself two tough questions:
Which parent can provide the most loving, supportive, and safe home? Which one has the patience to do what is necessary day in, day out, year after year?
What about finances? Is each of you equally able now to provide what your children will need? Or will one of you have to work more hours to make up the difference? Is child support going to be the deal breaker, enabling you to be 'held for ransom'?
Honest answers to these issues will show you who is more suited to being the primary caretaker (stay) and who is more suited to being the supporting parent (go).