[QUOTE=pseudoswede;25410170]My Firefox has become very sluggish, and I get "running out of memory" messages and crashes.[/QUOTE

I've been on Firefox 64-bit betas for almost a year now. Otherwise, I'd have had to go over to Chrome:
https://ftp.mozilla.org/pub/mozilla....9/win64/en-US/

(In theory, Firefox is supposed to be introducing process separation one of these days, which should fix the memory issue even on 32-bit. OTOH, I've been waiting for that even longer than I've been waiting for 64-bit to go out of beta.)