The main rule of thumb that I follow in these cases is: “Use WordPress multisite if it gives you clear advantages, not just because you can”.
Mike Epstein explained this pretty well in the “Don’t use WordPress Multisite” post.
This question is also answered on Quora before: Are there any disadvantages to using wordpress Multisite? and I believe that covers most pros and cons of WordPress multisite as well.
Your use case, which holds a couple very similar websites, is clearly one where it has mostly only advantages to use multisite.
BUT: Important to note, is that not all plugins are compatible (or working 100%) in WordPress multisite. Some have obvious bugs because the developer never bothered to test.
Finally, one important thing: You can always export one of the websites that deviates too far from the ‘standard’ within your multisite and set that up as a standalone install.