This is what I do:
# Run tests and generate .xml reports
mvn test
# Convert .xml reports into .html report, but without the CSS or images
mvn surefire-report:report-only
# Put the CSS and images where they need to be without the rest of the
# time-consuming stuff
mvn site -DgenerateReports=false
go to target/site/surefire-report.html for the report.
After tests run, the rest of the two run in about 3.5 seconds for me.