CudaText is a wonderful software. I found it after a few years of using SublimeText (and after my current employer doesn't allow me to use it). CudaText is fast and has many plugins to manage every need as Notepad++, despite some roughness in some parts of the user interface compared to ST.
Excellent performance for big files (some might know Universal Viewer for this task, it's from the same dev), simple and efficient like Np++ while still having some more advanced features. Very customizable through options and plugins.