Most counties do their own GIS work to keep tax records. When tax dollars are on the line the GIS data gets a lot more accurate
and is kept up to date. When a state or federal agency does a federal land data set they tend to make errors because land changes hands so much and they only have PLSS data to work with, which is great until you have land parcels that don't follow a quarter-quarter section line. Many of those state and federal data sets were created 5 to 10 years ago.
Trust me. We've fixed many, many errors by taking the time to get the information from the right people. That's why game an fish agencies endorse our product. They don't like wasting their time writing trespassing tickets. They want to catch poachers. They have seen the other map's errors and they steer folks towards our product to reduce the chance for error / tickets.