Congratulations. Yes...do a thorough walk thru. Have them demonstrate and then you return demonstrate every thing. Turn all lights on and off. Open and close all cabinet doors. Take a flash light. Look in all cabinet spaces. Turn all electronics on. Good idea to see the roof if able. Inspect all the seals and caulking. Take video if you need to. Have them demonstrate how to winterize the unit. Do a search on here. Plenty of info on doing a good PDI on here.