I'm curious how filtering proxies like Privoxy, Proxomitron, Proximodo/Proxydomo, etc. compare --- it's an extra (local) hop of network latency, but those are pure native code. I've been using one for a long time (ever since I heard of them) and it effectively works across all the browsers on the system, even those built-in to other apps (often only for the purpose of showing ads...) Even for those who don't routinely use multiple browsers, given how increasingly user-hostile and unconfigurable they are becoming, I think it makes sense to move filtering into its own application.