We evaluated few of such available drag-drop WordPress Page builder solutions and found the following 10 to be the most effective ones and that too which are available for Free.
1. SiteOrigin Page Builder
2. Unyson Framework
3. WooRockets Page Builder
4. Live Composer Page Builder
5. Elementor Page Builder
If you are looking for a detailed review on Elementor, I suggest you to check this blog post on WPCity.
Thanks for including Page Builder Sandwich to your list. Would love to know what you think about PBS!
All the best,