Re: "no problem giving Apple a pass" - One major difference
"Personally, I find Edge doesn't massacre my memory and loads pages fast, both things that matter more to me than OS politics."
The new (58) Firefox is faster still and configures well for security and privacy with a load of good extensions (Privacy Badger, Ghostery, NoScript, uBlock origins, etc).
It is also phenomenal for memory management for those of us who do breadth + depth research on the Internet - a dozen windows with hundreds of open tabs, with no slowdown and memory footprint less than 1 GB. (disclaimer - underlying OS is Linux for me, but if you can get 600 tabs open under Linux, I suspect you may well get half that, at least, under Windows - the Linux Firefox improved quite markedly when they went to the new engine and architecture).
The new Firefox is also multi-core aware, and will use them while avoiding treading on other processes.