I like that it's very flexible, has loads of plugins available out there (which is great if you're looking at something similar). It also supports lotsa different languages which makes development much easier than with other platforms such as wordpress or drupal in my experience! As others have mentioned - not all features are easy/well documented but this can be improved by them over time too :) We've been using backdrop since 2013 so we know how well its developed now compared when first released back then!! If your after flexibility & support from an already established platform go ahead otherwise look elsewhere maybe? Our main use case was hosting our website without having full access rights ourselves through another provider ecommerce store integration etc.. Supportive team behind us who helped get things setup initially along side some really good tutorials online made life alot simpler during set up phase plus they were.