1. Multiple cursors!! (and how easy is to use them)
2. Real-time preview of regex search
3. Package Manager (easy installation and discoverability of plugins)
4. Jump to file, jump to function, jump to css selector.. (ctrl+p, ctrl+r, using fuzzy search)
5. Project tree in small font (many files at sight)
Edit: Here there is a bunch of good stuff: https://medium.com/@huntie/10-essential-vim-plugins-for-2018...