Have you verified what caused the crash via logcat? Firefox has never crashed in my case, not even once (but I'm not running a low ram device).

That was nearly a year ago because chrome with extensions then arrived, but I did verify it was caused by RAM (usage was growing as FF was loading these tabs in background), then I did set some tweak in about:config which made the issue a little less severe (open in new tab didn't start loading them), but it still crashed if I then manually switched tabs, FF did not unload previous ones despite running out of RAM.