For the sole purpose of testing which of the two extensions makes Firefox faster, I ran a test with both extensions equipped with the filter lists I prefer. Only one extension was activated in each test. After each test Firefox was closed and then reopened to run the next test. As a test I chose Speedometer 3.0 + Motion Mark 1.3. After these two tests it seems that Firefox + uBlock Origin Lite is the fastest combination. Speedometer + UBO Speedometer + UBO Lite Motion Mark + UBO: Motion Mark + UBO Lite https://browserbench.org/