ClearURLs now handles eTag filtering, therefore ETag Stoppa by the wonderful 'claustromaniac', who is a major contributor to the 'arkenfox' user.js project, is no longer necessary. I'm actually a tiny bit sad to have dumped ETag Stoppa, but efficiency supersedes the tears.
When Kevin R. added eTag filtering to his wonderful ClearURLs add-on, my first thought was whether it works as well as ETag Stoppa, so i asked him and this was his reply...
Both implementations are almost identical. I have oriented myself on the source code of claustromaniac and made some adjustments, so that for example the ETag Filtering can be switched off in the preferences and is included in the statistics of ClearURLs.
From a purely technical point of view both implementations do the same.
If that's not enough detail for you, you can read the rest here.