I've been doing Drupal for years. After working with SilverStripe on my latest project, I ... don't want to work with Drupal anymore.
SilverStripe is a real OOP/MVC framework, where your solution is defined in (easily deployable) code. And they make writing that code as easy as possible. The CMS layer is also completely separate (and optional) to the underlying framework layer.
Drupal is a frankenstein framework, with your solution defined in heavily abstracted database entities, which are a PITA to deploy. Features, Config Management (incl the D8 initiative), etc, I now view as giant workarounds to the real problem, which is: that stuff shouldn't live in the DB in the first place.
Drupal certainly has its pros... it's insanely flexible and modular, has proven scalability, 10s of thousands of free modules for anything you can think of, millions of sites out there (huge community, easy to find answers about anything). But dear god am I sick of wrestling with configuration GUIs and worrying about how to get the results of that up to production.