I've been a Firefox user for years. It was leaps above the other solutions available when I first discovered it, but as of late, the general slowness and high crash frequency have had me wondering once again what else is out there.
I like Safari for the most part, but really hate the default shortcut combinations--opt+cmd-f does not speak to me. Thankfully, I finally stumbled across a wonderful post that details how you can setup Firefox like shortcuts in Safari. It does require a small external app, but I haven't noticed it yet, and the speed of the shortcuts feels as if they're native Safari commands.
Take a look at Roberto's post here if you're interested. Enjoy!