This is exactly what ETW was designed to help you measure. Running WPRUI with first level triage will measure CPU along with a bunch of other stuff. Enabling

This is exactly what ETW was designed to help you measure. Running WPRUI with first level triage will measure CPU along with a bunch of other stuff. Enabling ReferenceSet under memory Resource Analysis will measure memory usage. Chrome has an ETW provider, I poked around a bit and couldn't find any for FF (it looks like they register one for the JS engine?) I'm not familiar with how to solve the "page loaded enough but not done" problem, but IMO if you measure end-to-end times it's probably a close-enough proxy. Maybe measure several times and report on those statistics. (Edit: Taking a trace with/without the adblocker enabled should allow you to exactly count # of sampled cycles spent in the adblocker - easy to compare in WPA, as long as there are events emitted indicating page load start/stop). (Edit2: Using UIforETW along with Chrome 46+ will let you see ETW events: https://github.com/google/UIforETW https://github.com/google/UIforETW)