My editor of choice TextMate is usually launched from the terminal. I work a lot in a REPL environment and when I get a stack backtrace my terminal program iTerm2 automatically identifies paths in the stack backtrace, so I can mouse click them and open in TextMate at the correct line.
I use a separate git GUI client called Tower a lot, but I also use the git command line. I mix and match a lot.
I really dislike monolithic tools. If you try to do absolutely everything from the CLI you get many of the same problems as in a IDE GUI: You get too much complexity in your interaction. Too many special keystrokes and commands to remember.
I quite like the old NeXT idea of an IDE, kind of how the old xCode was when interface builder was a separate program. As you integrate more tools complexity just grows.
We already have a multitasking OS with windows. We where meant to use multiple tools and not just sit in one big maximized monolithic program.