The short answer is YES, you should.
The long answer: Starting with Divi 2.4, the Elegant Themes, brings a new way of working with your theme. Basically they introduce new features, which you only see in premium plugins like visual composer but the problem with those kind of plugins, is that sometimes they look much better in back-end then in front-end.
The new Divi Builder adds great options when it comes in configure each page and post. You have tons of modules you can add, and plus each module comes with their unique ways to customize it. If the module interface is not enough you can always use custom css classes to each modules and then use those classes to target that particular module, to apply custom css rules to it.
Also a great feature to mention here is the Divi Theme Customizer, which allows you to choose from 3 different header types, actually it gives you the options to choose how the logo and the main navigation menu, should behave, this option among other great options: setting up fonts, font-sizes, colors, and also the overall layout of your entire website, makes Divi 2.4 a great theme which basically gives you endless options when it comes to customize your theme.
Now I see many “developers” complaining that Divi 2.4 mess up with their websites. Well yes it will mess up with your previously installed Divi, if you used poor coding, specially when you used Css to customize the default way of how Divi works. I did make an update from Divi 2.0 to Divi 2.4 without losing anything.
For those who might have problems with your updates, you can leave comments bellow, and I will do my best to help you with that, or you can visit Elegant Theme Forums, and ask for help, and I will assist.
In the end to answer the big question: Should I update my Divi ? The answer YES you should.