The difference in coverage maps between the example and your results in R2017b is due to the usage of terrain data that was added in R2018b. That release introduced the Longley-Rice propagation model as the new default along with automatic access to terrain data (Internet required), which results in more realistic coverage maps than the R2017b version you used.
The R2019a version of Antenna Toolbox added a couple of other terrain features, including the ability to import terrain data from DTED-files and support for the TIREM propagation model.
