I wish Waterfox was better supported but can live with the fact one person is doing the work on that fork. Otherwise I find none of the objections over the current build of Firefox compelling enough to abandon it. It works and is still easy enough to edit with about:config. The phone home crap can be shut off and the pre-loading of websites containing questionable content was also easy to shut down.
Running IE 5 on System 9.x was pretty comfy as I remember it. No worry about botnets and malware for System 8 or 9.