We plan review everything with some exceptions for fire. Bigger projects get sent out for some reason even though structural, mech, plumb and elect still are in house. We also do all inspections, except special inspections, in house.
The city I live in has a different approach. They plan review in house, which takes a very long time and multiple phone calls to get through, then they outsource the inspections. A few inspections for my remodel were more like drive by's except that they rang the doorbell, peeked inside the doorway area, got a signature from the contractor, and moved on.
Which explains all the problems that I have had to fix in my new home, outside of my remodel.