If you are dealing with large text files of JSON or XML of 1MB or larger you can turn the buffer into Fundamental mode and turn off line numbers. I’ve found th

If you are dealing with large text files of JSON or XML of 1MB or larger you can turn the buffer into Fundamental mode and turn off line numbers. I’ve found that the reason why large files are slow is due to formatting and linting and not the size of bytes on disk. With fundamental mode and no line numbers it feels as fast as Vim or Sublime to me.