You're right. We keep control over the experiments so that we know the consistency of the data we're measuring. A problem with using our full release channel T

You're right. We keep control over the experiments so that we know the consistency of the data we're measuring. A problem with using our full release channel Telemetry is that so many users have so many variables it's hard to compare apples to apples. E.g., was their performance issue caused by a setting, an add-on, the site they were on, or Firefox itself? Test Pilot experiments give us some controls and parameters on the experience so we have a clearer idea of what's causing what.