The vim command is doing a search and replace over all text - Rename in Visual Studio will restrict the change to class/method/.... name definitions and calls to them.
Ah, so instead of having to hand-roll your own really complex regex that would limit the scope every time, VS automatically limits the scope of the renaming for you. That is pretty nice.
It isn't about limiting scope, it's about parsing and understanding the language. A refactor can change every file in your project (for example, renaming a global variable named 'i').
And, yes, it is very nice. Eclipse comes close with Java but, last I tried Vim and Emacs refactoring plugins, they were nowhere near as good or even very discoverable/usable).
No, you operate on different levels. A regex replace works on the text of your source files, a refactoring rename in Visual Studio or Eclipse works on the symbol.
