If those are your only concerns and are willing to customize Firefox with some simple steps (1-10 will take about 10 minutes), you will be fine on Firefox 6 and you would have been fine on 4.9 had you seen my notes below. Step #10 used to take 5 minutes longer but the defaults in the extension are setup as wanted. Step #31 will take care of ability to restore your tabs by deciding at the time you exit Firefox -- and even if you make wrong choice there you can still pick up your previous session through the History menu. Step #41-46 improve styling for me don't lose any toolbars, and eliminate much of the wasted space -- can't do anything about the Windows title bar it is double the needed height. Newer Firefox version also have '''app-tabs''', which will stay open forever. Forever is shortened by messing up the content or accidentally closing them and not restoring them immediately. In other words don't count on them, bookmark them for when you do have to or want to restore them. Despite developer hype app-tabs should not be considered permanent nor treated as open bookmarks -- they certainly are not bookmarks they belong to your session data (browsing history). You can make '''Firefox 6.0''' look like Firefox 3.6.*, see numbered '''items 1-10''' in the following topic [http://dmcritchie.mvps.org/firefox/firefox-problems.htm#fx4interface Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 4.0 thru 6.0, look like 3.6)]. ''Whether or not you make changes, you should be aware of what has changed and what you have to do to use changed or missing features.'' * http://dmcritchie.mvps.org/firefox/firefox-problems.htm#fx4interface There is a lot more beyond those first 10 steps listed, if you want to make Firefox more functional. <br><small>When you do update, please return to this post make the changes you want based on the llinks and then hopefully mark "Solved" one answer that will best help others with a similar problem -- hope this was it.</small>