Some Tips to help you when you develop on Errbit
Running spec on multi-threaded mode
If you want do it, you need install in first the gem 'test-queue'
gem install test-queue
After you just need launch the script with adapting runner of mongoid.
In my case, the complete test suite down to 2min after a 16min long before.
Avoid running acceptance test with phantomjs
bundle exec rspec spec --tag="~js"