bcvi will also let you use your editor of choice - it just happens to use gvim "out of the box".
If you're already logged into the box with SSH then being able to type 'vi file' on the server and have the editor window pop up on your workstation actually turns out to be really handy. IMHO it's easier to set up than sshfs too.
If you use GVim on your mac then it should work fine.
If you use a different editor then it should be pretty easy to hack up a plugin that launches your preferred editor instead. The plugin API docs give an example of launching GNOME gedit: http://search.cpan.org/perldoc?App::BCVI::Plugins
"I never run gvim, are there any real advantages that I am missing?"
If you're an Emacs user, probably no particular advantage. I use GVim because as a GUI app it allows me to use my mouse for stuff like selecting areas and copy/pasting. I also like the workflow of having my file open for editing in a separate window and getting my shell prompt back straight away.
But yes, of course you can do the same stuff with sshfs and if that's your preferred tool you should definitely use that.