Ideally I would like to track code coverage, however due to an issue we're having with Salesforce, it's taking 12-24+ hours to run all local tests, crippling our ability to run unit tests nightly. I've discovered that when turning off code coverage when initiating test runs via the tooling API, test runs take significantly less time. We have been working with Salesforce support on this, but as a workaround it would be very useful for us to turn off code coverage for Unit Testing jobs.