I find it way easier to visualize a diff in a gui. That's primarily what GitX brings to the party. For almost any feature other than git log and git commit, you still need to hit the CLI.
(I DO think this means there's a great deal of potential profit available to someone who releases a GREAT git gui for OS X)
You probably aren't our target market (people new to Git) - but we are working on Git UI for OSX aimed at making the most common commands easy to perform. http://gitmacapp.com/download
My VCS of choice has Qt-based GUI flavours of almost all commands on windows, OS X and Linux. The only ones I ever use are annotate, log, diff and occasionally commit.
I see that that wasn't clearly written. What I meant was "I don't consider a CLI to be a legitimate interface (in general)". Obviously Git's is "legit" because, as you say, that's how it was designed. But I'm against such designs.
You can't use Git completely without a GUI [1] and not having everything in a GUI means I'm forever typing some command and then typing another command (or several) to make sure what I expect is actually what happened. To "visualize", if you will. In a GUI I could just see it and this would save a lot of time.
[1] Diffs are visual (vi is a GUI). I'm sure some clown will show how it's possible to use ed or something so you can really do everything without a GUI, but the effort that will take demonstrates my point nicely.