Pros:
Powerful ability to clone a Joomla installation and update it. Able to sync users. Only real alternative currently available. One click updating of distributed installations.
Cons:
Documentation is minimal, still being developed (though there are some video tutorials on their site). Difficult to know where to start, creating first subsite is not intuitive. Difficult to “undo” mistakes as you make whole new Joomla installations.
Overall: 4 stars
Although not for the faint hearted, MSM Pro offers some very powerful capabilities to install and maintain any number of Joomla websites. The concept is relatively simple. You install the component on the “main site”, you are then able to create subsites in the component manager. This process is relatively simple, but has some hidden complexities. Going to the MSM manager, you just create your subsite. Then you have to duplicate the files that form a Joomla installation. This is relatively easy, except figuring out exactly where these files will come from. It took some trial and error, but the first subsite you create will copy its files from the main site you are working from. Its then well worth setting up this site to be able to clone it, have the right templates, components you need etc. Subsites you create can run off the same SQL database as the main one, with different table suffixes, or you can designate a different db.
Once you have your subsites set up, MSM begins to shine. Need a new template added, or a component? Install it in your subsite you have made to clone and one click will copy that template into all your selected subsites. Same goes for synchronizing users.
As mentioned above the documentation is thin, though there are numerous flash video tutorials on the elearning site. It took me about 4-5 hours from scratch to get 6 working subsites. One issue seems to be how to undo/delete sites. You can delete them from the manager, but this does not seem to either remove the Joomla files or the table SQL entries. Overall though, a welcome addition to anyone that is trying to maintain several Joomla sites that have similar installations, elearning or otherwise.
Website: www.elearningforce.dk