I haven't used PHP for quite a while but personally I was more satisfied with the SublimeText than Atom but the difference between those two was minimal and I even could say it was "matter of taste". I switched back to SublimeText, because I had been more satisfied with the auto-completion and snippets features in my setup and I couldn't find any plugins to Atom which will give me comparable feel. Today, I guess many add-ons for Sublime are outdated and/or not possible to work with, so Atom might a better choice.

Except PHPStorm I know many developers who got used to NetBeans IDE.