Privacy and feature set. Haven’t found another browser that meets all of my criteria:
- respects my privacy
- vertical tab support
- some form of tab stacks/groups
- can hibernate tabs to save battery/reduce ram usage
- can bind almost any feature in the browser to a keyboard shortcut
- mouse gestures
- customization options for all the little things - always open bookmarks in new tabs, custom search engines, ordering of items in context menu, etc