That. I wish I could buy a billboard in front of wherever Mozilla's people work and put up:
If we wanted Chrome, we'd use Chrome. Bring back Firefox.
Everyone who used Firefox before the versions numbers went haywire
in MASSIVE text as a daily reminder of the old glory days.
Seriously, I shouldn't have to rearrange and twiddle with everything to get Firefox as much like 3.6 as possible every time I install it. What true UI improvements have we had since then? I can think of two: tabs that don't resize while I'm hovering on them, and tab groups. Why was the rest of it randomized?
Also, what's with the stupid launch defaults? I close Firefox when I want a clean slate, not a glorified minimize. "Restore my windows and tabs from last time" is antithetical to the whole idea of closing all the tabs! Can you imagine if Windows restored all your programs and junk from last time? People would come unglued.
Also, we live in an age of large LCD displays. I can spare a few pixels of screen space to keep the bookmarks and buttons I use all day long visible instead of burying them somewhere underneath gloss and shiny.
One last gripe: Tools > Add-ons should take me to Extensions, not the "Wonderful World of Stuff You Could Bloat Your Firefox With." I go to Add-ons to remove extensions other programs installed without asking far more often than I feel the urge to add bloviated toolbars. Speaking of which, can we finally make Firefox ask before allowing programs (like nearly every AV, Skype, whatever) to hang their useless (or worse, Google-search-invading) lampshade in Extensions?