My experience with IDEs is limited to Visual Studio and Eclipse. Have toyed with IntelliJ - but didn't go deep with it.
For me IDEs are slow, complicated and the screens cluttered. There are so many panels, options, buttons, etc. All I want to see is the code. With vi and multiple screens I can have more than enough windows open. I let the compiler generate warnings and errors. With a fast machine running make I hardly ever have to wait too long.
Besides, cutting code is only about 30% of the effort in a project. Documentation, testing, support, meetings and more meetings take up the bulk of my time. I actually enjoy the time I get to do real work! Being more hands on feels good to me.
Because VIM works so much better for me than any IDE ever has. It just works, it's installed everywhere, I don't need graphics to use it (so I can use it on remote machines), it's fairly scriptable (this is the only thing I have to give the Emacs guys -- they have a proper programming language for scripting). Most importantly, I only need to know how to use one text editor, as opposed to some languages where you need to change IDEs to actually do anything (see: Xcode, Eclipse, Visual Studio, etc).
My sometimes-use of an IDE has zero to do with ease of understanding, but for the tools it provides that text editors don't, refactoring being the biggest one.
Efficacy depends on the language being worked with, of course.
Nothing against IDEs as i have used many in the past. Once i started working with a large number of distributed systems, having VIM or Emacs foo became sufficient.
For me IDEs are slow, complicated and the screens cluttered. There are so many panels, options, buttons, etc. All I want to see is the code. With vi and multiple screens I can have more than enough windows open. I let the compiler generate warnings and errors. With a fast machine running make I hardly ever have to wait too long.
Besides, cutting code is only about 30% of the effort in a project. Documentation, testing, support, meetings and more meetings take up the bulk of my time. I actually enjoy the time I get to do real work! Being more hands on feels good to me.