It can't be much fun being bounced back and forth, week by week between Mom's and Dad's. Maybe it's a little bit better than rarely seeing your dad (or mom), which is what we went through as kids. We relished those short visits for the feeling of 'belonging,' learning more and more about this man we called Daddy and his little world, and never doubting his love at the time.
Every kid's experience is different when a family is split. Most of them would probably say, "If only my parents were still together and really loved each other --- what a perfect world it would be." But life isn't perfect as most of us realize sooner than later. May God have mercy on these little ones!