As for the original topic: I use IntelliJ IDEA Community Edition professionally. There is *nothing* in the Enterprise Edition that would do my life easier (I don't do any of that JEE nonsense nor web-apps).
IntelliJ Platform and the IDEA Community Edition IDE are Apache 2.0 licensed. This means you can use it for whatever purposes you want, including writing proprietary, commercial software. It also mean you can modify the code of IntelliJ yourself, sell modified versions of it, anything like that, as long as you abide by the Apache license.
I have no use for it really. I'm usually programming on my desktop computer at home or if I am out and about and need to jot something down or have some free time to work on a project I always have my laptop with me.
I could see it maybe being handy if you are using public computers all the time though.