Tree Style Tab for me. I remember reading that it is not a matter of someone porting it to chrome but that the chrome UI does not support such tab flexibility. Sad times..

I also wish chrome would stop prepending http:// everytime i copy an ip from the url bar.

But by the standard of a url, it has to contain the http:// (or whatever protocol/scheme). Otherwise it's not a url.

https://en.wikipedia.org/wiki/Uniform_Resource_Locator

I am not arguing against that fact.

But if I copy a specific part of the url I expect nothing to be added when I paste it

Is it prepending it on copy, or hiding it for display in the url bar?

It's both.

Firefox does the same though?

> I put up with it's poor performance and instability merely for this one feature.

Ah, but performance and stability is exactly what Mozilla is improving with WebExtensions, Electrolysis and Servo/Quantum, so you won't need to put up with the poor performance and instability any more! What's more, it will still respect your privacy more than Chrome, be open source unlike Chrome, and allow you to configure it more than you can configure Chrome.

Baby / Bathwater

Firefox's primary distinguishing feature is the powerful plugin system. With that gone, it's just another browser.

for me it's Tab Groups (actually one of the Extension the author wrote). If that is gone, there is no good reason for Firefox over Safari

I would use the last version of Firefox that supported Tab Mix Plus until it no longer worked with the web in general. At that point I don't know what I'd do.

Looks like ESR 52 will continue to support XUL addons, and get regular security updates, well past the release of version 57 which is the estimated version for the cutoff. We can "vote with our feet" somewhat. If a large number of users switch from 56 back to 52 ESR instead of "upgrading" to 57, we will have some actual numbers to show.