David,

The user interfaces, however, are quite different.

In my case I have isolated the DLLs FF 52 uses to set up an SSL connection,
and am fully ignoring the browser part.

But ... Reading your description about seamonkey, it might be a good idea to
take a peek - Although I'm using FF 52 ESR, thats not by choice*, but by
necessity. An earlier version got rejected by more-and-more websites,
because it doesn't support the newer encyption standards.

*just to name a two dislikings: It keeps phoning home, and the NewTab tiles
do even worse.

But although I've looked for it, I cannot seem to find any comparision chart
in regard to which version of FF supports which encryption standards
(otherwise I've probably would have been using an older, good-enough-for-me
version).

At the least, SeaMonkey does not protect me from things from
which I definitely do NOT want any protection (e.g., extensions
not hosted by the Mozilla Web site).

To be fair, FF 52 still allows you to bypass that check (without which I
would not be able to run my own experiments in that regard). It keeps
warning (nagging) you about it on the extension page though.

But yes, it has become a bit too nannying for my liking, as well as too
flirty with advertising.

Regards,
Rudy Wieser