I do most of my development work in Jetbrains IDEs and am a huge fan but if you don't keep the environment open 100% of the time it takes a long time to bootstrap. texmate is great for fast one offs
I usually have three instances of IntelliJ open at the same time with large Java projects in them. One I'm working in, another a colleague is asking me questions about, another to lookup some related code, et cetera.
I use Atom for my quickie projects here and there, but you really can't beat an IDE. (IMO)