I'm using Pale Moon but not because standard FF was crashing (I don't remember the last time it did), I just hated the new UI.
"A week ago, Mozilla shed some light on its future, laying out a plan on how the browser is going to dramatically change in the upcoming months. While most of us understood "Chrome extensions are coming to Firefox," it is not as simple as we all thought.Please God, Don't Let Mozilla Ruin Firefox - Softpedia
"... The Mozilla dev team has a pretty solid plan on how they can change the browser "always crashing" image, and even if we don't like it, this includes a severe and very profound change to Firefox's core code. ..."