Please see the linked articles. Be sure to use Feedback if you feel strongly, and also vote on this thread to say you have the same problem.

Also see the open thread

• The I-do-not-like-Firefox-29-layout topic /questions/998106

Firefox remains customisable. Maybe some of this information helps explain the improvements.

Try the new design, if it does not grow on you there are ways to make it more like the previous version.

• See Learn more about the design of the new Firefox version 29
  Common questions after updating to Firefox version 29
• How to make the new Firefox look like the old Firefox
  https://addons.mozilla.org/firefox/addon/classicthemerestorer/

One of the developers recently posted this explanation

MikeDeboer said

Each setting you see in a computer program you use requires work; when a developer wants to build something new or improve something, he or she has to go through each related (hidden) setting and test if it still works like before and do that on each platform Firefox runs on. That's Apple's Mac OSX, various flavours of Linux and various flavours of Windows, including Windows XP. This costs time, lots of it, and that amount grows exponentially with each setting that's added. This comes on top of our work to continuously fix, improve and innovate Firefox. 
 
 That's why we also removed the tabs.onTop preference. Awesome community members, who were unhappy about that change, created the Classic Theme Restorer add-on. They deserve our collective hugs. 

• For more linked help articles and the full quote please also see
  Why have you changed design in new Firefox 29.0? /questions/998084#answer-566525

Are you having any particular problem ? We may be able to suggest a workaround.

Have your say. Note Firefox 29 is to some extent work in progress.

People helping here are mainly volunteers and users of Firefox like you and I. If you feel strongly about the new changes I would suggest you make a short comment and provide feedback on https://input.mozilla.org/feedback for the people who decided on the changes to actually see it.

Personally one of my major gripes is that the upgrade happens without prior warning of major changes, and then we are left in a changed Firefox trying to find out what works still.
Sure the new features can best be demonstrated from the new version, but some prior warning with a chance to read up about the changes would surely help.

• As mentioned in Firefox 29 screw up - Please consider USERS How to fix this??? /questions/999831

Thanks. After some effort I have been able to restore some of what I liked about my previous Firefox layout. I agree that having notice of changes would have been good. Even better I think would have been to have the new Firefox 29 layout as an optional skin. I can accept the hamburger button and have even started to like it, but the other changes to my layout are a problem, especially that I can't dock the address bar in a toolbar like I could with Firefox 28 as well as making users install add-ons to restore their previous interface options. I hope with the next version of Firefox there will be more thinking about how to give users options for their interface preference and introduce change in a friendlier way.

Most users of Firefox have customized this browser so they can use it in their work. It's a work tool and it's unreasonable to expect users to stop WORK to restore the features and customizations already made just because "someone" decided Firefox needed a "new" look. Between the shutdown bug (caused by setting history to delete at exit--a known bug with previous versions!) and the drastically changed appearance, Firefox 29 caused a lot of grief. There are alternatives to Firefox...is the goal to drive long-time Firefox users to select one of the alternatives?

I always tend to be behind the curve regarding updates, since the first few versions are 'buggy', and by the last iteration they're usually fixed.

Not so FF29.0.1, which I've just installed. v.29.100.100 couldn't repair this. What WERE you thinking, Mozilla?

This is truly awful. Everything that I liked about FF has been obliterated, and it's taken an afternoon trying to get some semblance of useability out of it, since all my carefully arranged icons are now all over the place.

Appearance X Customization X Intuitive Interface X

I dread to think what FF31 looks like.

Please don't force me to use Chrome, Mozilla...

Fx29 when it was released was not intended to be any leading edge Pre release version. It was the safe, secure, supported, main Release. By now you should be on Firefox 31.

If you stay on old versions you will be forever vulnerable. Once security holes are fixed and the changes publicised & Released the bad guys have a greater opportunity to exploit them on anyone who fails to update

• Listing https://www.mozilla.org/security/known-vulnerabilities/firefox.html

Firefox 31 by the way looks much like Fx29 & Fx30

• https://www.mozilla.org/en-US/firefox/31.0/releasenotes/
• https://www.mozilla.org/en-US/firefox/32.0beta/releasenotes/

Instead of being behind the curve have you thought of trying the opposite. Firefox's rapid release means it spends six weeks in each of Nightly, Aurora, Beta then Release.

You could actually try the Beta channel. (Not for computer novices, but no need for high end IT skills) At first thought such an idea is counter intuitive, but it does have advantages for those with ordinary computer skills. (It is an advantage for instance to be able to copy and paste, navigate your file system, and follow links and written instructions that include jargon like copy and paste.)

• It is more of a Release Candidate than a traditional Beta. It is pretty much reliable and stable.
• You see changes six weeks in advance. That gives you six weeks to figure out a workarounds or solutions to problems.
• No more how do I cope with the unexpected change or need to risk an insecure version.
  • You always have a safe supported downgrade path, to a version you know works - The Release, (that you will have already used in the prior six weeks whilst that was in beta).

Bugs / Chemspills Should you find a fault or problem report it and it should get fixed. The more that is found at this stage the better. You said

since the first few versions are 'buggy', and by the last iteration they're usually fixed.

After Firefox is released most versions have had a point Release often referred to as Chemspills needed to fix urgent problems. If these issues were found earlier in this train of testing the bug would not become a fault into the Release. The reason the majority of chemspill bugs get through is that Firefox is complex, multi OS multi platform and highly customisable so plain and simply not enough people test it to discover all the problems prior to release to the approaching 1/2 billion user base.

I am posting this from Firefox 32

This topic is by the way off topic and outside the scope of this forum.

Personally I will not close this thread yet as I am not aware of anywhere else deliberate feature regression and related development issues can be discussed within Mozilla, and this thread has not degenerated into trading insults. I know there was talk of finding somewhere so that discussions could be directed to an appropriate official Mozilla location but I can not say I have noticed that mentioned again recently.

If you have a very specific problem you are trying to fix in the current Firefox 31 Release you would do best by starting a new thread.

To start a new thread by asking your own question and giving full details.

1. Please use /questions/new/desktop
2. Please try to follow the prompts and include troubleshooting info when you do that. (There is a green button to automate the process. Use that, or if you encounter problems doing so mention that in the new thread.)

Thanks