Unfortunately the choice isn't as easy now, personally. I'm stuck having to use an older, non-Quantum version for my daily browsing following Mozilla's decision

Unfortunately the choice isn't as easy now, personally. I'm stuck having to use an older, non-Quantum version for my daily browsing following Mozilla's decision to obsolete their previous addons as of v57 (and having since deleted them from their servers). Previously Firefox was a no-brainer choice for its deep customizibility and functionality it afforded addons, which primarily distinguished it from Chromium, however since the move to Quantum I have too many addons without an equivalent to switch, with a couple favorites that did migrate to WebExtensions offering an inferior experience. Vivaldi would be my second choice should I be forced to switch since its integrated features more closely match Opera's original features, albeit less extensive. Mozilla felt the need to do what they did in that regard and I understand the various reasoning for the decision however the way it panned out didn't make for a browser I'm currently interested in upgrading to, sadly.