There’s another 64-bit Firefox build called Waterfox that I use, along with 64-bit Chrome. I’ve found that Waterfox is superior to Chrome for streaming media- on my older hardware, audio and video content “staggers” a lot in Chrome.
I used Waterfox until I discovered Pale Moon. I think Pale Moon is “optimized” by removing some little-used features. At any rate, both were excellent products.