- The title bar has vanished - I had to install an extension to get it back
- My theme changed all the buttons around so I couldn't find them - I installed a firefox 3 theme to get them back to the right order.
- My personal menu extension was ruined so I had to install another extension to have my single button menu shortcut back
- It took away the 'save and quit' option when I close my tabs. Thankfully I found instructions for the "about:config" section to get this back.
- It changed the order the tabs are opened. Ditto with the "about:config" settings.
- My personas themes were disabled. "about:config" settings had to be changed to get them to work - this was a comment by user: Steph in the theme reviews.
I know that new editions of things usually make some changes but some of these are fundamental. The 'save and quit' button for example is firefox's trademark. Why they'd get rid of it is beyond me! Personally I HATE theme changes. Basic updates I understand but people get used to how something looks. It should be a chosen option - include the new theme or save the old one and just make the basic changes. We all want to save time and continually learning a new layout is plain irritating and idiotic!
Result: Firefox 4's layout and interaction sucks!!