Anyone had experience with a DOF property tax insepction?

I submitted the paperwork to the DOF on March 1st to get my property taxes adjusted after a gut reno (Class 2 SRO to Class 1 2 Family) and the DOF immediately started calling me to arrange an inspection for assessment purposes. A terrifying thought considering the vagaries of property tax in this city! Has anyone else been through this before and have any advice on what to expect and how to handle it?