I really like Atom. I used to use Notepad++.
Two things I cannot find in Atom that I can do in Notepad++:
Double-clicking on a word and seeing it highlighted in the whole document.
This is really nice to have to easily find something. While there is a search function in Atom that does the same thing with a few more steps. this little double-click feature is quicker and more convenient.
Save A Copy
This is really nice when you want to save a file at a certain point for making different versions.