I generally use Firefox as my main browser. However, I've been leaning on Chrome while the whole post-XUL extension apocalypse settles down and session managers in Firefox are back on par to what they were prior to the switch to web extensions.

I very much miss Session Manager (from Mozdev) on newer Firefox releases. The WebExtensions based session management extensions are still not as rich or as reliable as that one. So on machines I control, I use an older version of Firefox so that I can rely on Session Manager and a few other extensions from the XUL world.

Firefox 52.x ESR, which does work with XUL extensions, would remain a supported choice until September 2018 (a couple of more months from now). After that, there wouldn't be a Mozilla supported browser that's not exclusively WebExtensions based, AFAIK.

> while the whole post-XUL extension apocalypse settles down

It hasn't settled yet? I'm not missing anything in my Firefox (but I don't know about session manager addons since I don't use any).