If users are comfortable with Mozilla having the ability to remotely modify aspects of their browser, for example, via:
Shield Studies (A/B testing, silent feature toggles),
Normandy Recipes (remote preference changes or add-on installation),
Telemetry Framework (performance, usage, and hardware data submission),
then Firefox is the appropriate choice.
Mozilla’s model assumes a level of ongoing participation in a product-improvement ecosystem. This benefits many users who trust Mozilla’s intentions and appreciate features being tested and fine-tuned based on real-world data. It is also useful for those who want to contribute indirectly by enabling telemetry or participating in opt-out studies.
By contrast, Ungoogled Chromium explicitly avoids this model. It assumes users prefer a static, predictable, and non-remote-controlled environment, where changes only occur via deliberate system updates. No third-party has the ability to reach into the browser and adjust its behaviour post-installation.
In short:
Firefox is best for users who trust Mozilla and value active participation in its development model.
Ungoogled Chromium is best for users who prefer strict local control, no unsolicited changes, and minimal upstream influence.
