I think it is worse for children to see arguing and bickering than living separately with each parent or however it is decided.
It is great if the parents can get along as I did with the father of my children, however I think it would also be difficult if they did not get along, and I often hear stories about one or other parent being nasty and mouthing to the children and not allowing visits etc, or making them difficult.
I find this disgusting as I believe that CAN affect the children and they are the innocent people in all this.
So, I think, split, if you are constantly arguing, and children can tell these things also.