When I lived in Chicago I had a chance to review the Cook County land records. I am not sure if they are still using these procedures, but at the time I thought they were great. They had both titles and Torrens registries. They had the traditional grantor/grantee index. They also had tract books that contained complete histories for parcel of real estate. It was my first experience with the grid system of legal descriptions also. I found it to be a much better system than the old fashioned metes and bounds system used here in Connecticut.