Easy to use, 100% customizable, you have the hand on ANY HTML output and it's based on the MVC design pattern, so it's clearly OOP, with easy autocompleting. ".ss" extension is probably one of the best I've used as well. I've made modules probly more easily than on any other CMS (beside Drupal 8). When it comes to explain to my clients how to administrate their websites, they rarely come back to me after that. Upgrading is quite easy as well. The administration is really easy to understand, you can add custom tabs almost anywhere and manage almost any types of fields (varchar, text, boolean, file). File uploading is easy as well, form submissions is a real peace of cake. I also really like their beginner tutorial, it covers almost everything Silverstripe offers out of the box. Their documentation is quite easy to manage as well and their API does the job!

I liked how straightforward the UI was of this CMS. It was refreshing coming from Wordpress where its so overcomplicated. I felt like I only saw what I needed to and didn't have too many features available that I'd never touch. Navigating through the CMS was easy as well. User-friendly all around.

I like how simplified the UI was. You really only had access to exactly what you needed. Unlike WordPress where you have unlimited options that you never touch.