Hi Dan, My cousin, who has seen countless divorces, recommended for me to file first. I dont know if it gives an advantage in the long run. I do know that by filing first you can possibly be the one to dictate by a status quo order that the kids stay where they are and you control the timing of locking down shared accounts.
The drawback of filing first is that your W would be very angry when she read the initial petition. Most attorneys will probably use a boiler plate asking for everything. I even told my W that what was being asked is not what I wanted, but she still threw a hissy fit.
