I know for us, one of the unforseen benefits of the 50/50 was the removal of Child support since we both had DSS equally in the year. It wasn't our plan when we started, but it was a perk.
I think this is great if you both work and make the same amount of money and own roughly the same assets. But it couldn't work for SAHMs or SAHDs. They need child support until they start working - and often for many years afterwards.
I believe that most states will require that the higher income parent pay CS to the lower income parent in the case of 50/50 custody. I believe that in many cases it works as follows:
Calculate how much the low income parent would pay in CS if the high income parent had majority custody. Then calculate how much the high income parent would pay if the low income parent had majority custody. In the case of 50/50 custody, the high income parent is asked to pay the low income parent the difference between these two figures.
Example: say you are in a state that uses a simple formula of 20% of net income for CS. Then let's say parent1 nets 20,000 and parent2 nets 100,000. Parent1 would owe 20% of 20,000 or 4,000 if parent2 had majority custody. Parent2 would owe 20% of 100,000 or 20,000 if the situation were reversed. In case of 50/50 custody, parent2 pays parent1 20,000 minus 4,000 or 16,000 in CS.
If the parents have the same net income, then the amount each hypothetically owes the other is the same, and the difference is 0. So no child support is paid in this situation.