Session Manager is wonderful, but not perfect. Rated 5 out of 5 stars
Session Manager is necessary. Version 6.02 of Firefox is very unstable, far more unstable than version 3.6.20. Firefox crashes often when there are 100 tabs open, a situation that is common when doing research.
Session Manager is wonderful, but not perfect. Often it does not restore windows to the size at which they were saved. When restoring, apparently all tabs are re-loaded from the internet, instead of from the cache.
See the "reload all restored windows" options
It's misnamed since it's function has changed, but unchecking the "reload all restored windows" option in the General Saving & Restoring options will cause Session Manager to restore sessions from the cache (if possible) instead of from the Internet.
Excellent, with minor flaws Rated 5 out of 5 stars
The Firefox Session Manager add-on is necessary for those who do extensive research online. If many Firefox windows and tabs have been open for several days, through several system hibernations, Firefox becomes unstable, and even corrupts the Microsoft Windows operating system.
(The Firefox browser instability and memory hogging has been reported many, many times over several years, but has not been fixed. The problem is especially severe when more than 20 Firefox windows are open, with 5 or more tabs in each window.)
Using Session Manager, when Firefox becomes unstable it is possible just to re-start the Windows OS. That is seen by Session Manager as a Firefox crash, and all Windows and tabs are saved automatically. When opening Firefox again after re-starting the OS, Session Manager then offers to open all Firefox windows and tabs as they were before re-starting. That allows researchers to continue from where Firefox became unstable, with a fresh initially stable instance of Firefox.
Firefox Session Manager is not perfect:
1) In Firefox > Tools > Session Manager, 3 menu options are at the bottom of the list, Open Session Folder, Session Manager Options, and Reopen Closed. If there are a large number of session files listed, those 3 menu options are below the list of old session files, and may be hidden if many files are displayed.
All menu choices should be grouped together at the top. The list of files should be below the menu choices.
2) There is good documentation of Firefox Session Manager at http://sessionmanager.mozdev.org/options.html. However, the keyboard shortcuts available in Firefox > Tools > Session Manager > General > Keyboard Shortcuts are not explained.
It is possible to write Ctrl, Alt, and Shift for the Control, Alt, and Shift keys: Alt+Ctrl+Shift+M means holding down the Control, Alt, and Shift keys simultaneously and pressing the M key. Or, you can just press those keys, making sure the letter or character key is last.
Session Manager apparently does not accept key combinations that include the Windows key.
Rated 4 out of 5 stars
If you often have many windows and tabs open, Session Manager is necessary, because of the instability of Firefox. If Firefox crashes, and you don't have Session Manager, you will lose your work.
There are two areas in which Session Manager is less than perfect. When re-loading a session in which there are tabs that require a log-in, Session Manager may ask for the master password many, many times.
Second, Session Manager does not remember the window size of each window.
Session Manager v0.6.8 fixes a bug. Rated 5 out of 5 stars
Version 0.6.8 of Session Manager fixes a bug in previous versions. Previously, when there were many windows and tabs in a session, it was not possible to de-select or select individual tabs or windows. Now that feature works. Tested with Firefox 3.6.7.This review is for a previous version of the add-on (0.6.8.1).
Beware of bug in version 0.6.7.4 Rated 5 out of 5 stars
When re-loading a session, version 0.6.7.4 of Session Manager does not allow me to choose which windows and tabs will be re-loaded. Sometimes double-clicking will toggle the check marks, most of the time it won't.
New users should be made aware of this. That's the reason for submitting the problem as a review.
This would normally be submitted as a bug report, but submitting a bug report requires that your email address be made public! Making an email address public causes a huge amount of spam. I suppose that Mozilla Foundation's way of discouraging bug reports.
Otherwise, I have found Session Manager to be excellent. It is absolutely necessary because Firefox is unstable and crashes often if you open many windows and tabs and put your computer into hibernation or standby.