no, it's not.  it's a slightly more complex sRGB equation which as bagginsbill has posted long ago.  it's what i use on my own materials.  i can link you to a bunch of renders showing the difference.  more accurate sRGB materials and GC are close, though significantly different for the majority of the lighting situations i made based on reference photos (too light and too desaturated).  enough different that i really, really, don't like using GC.  still, uncorrrected gibberish renders (sRGB textures and colors in a linear render displayed on an sRGB device) were just plain way off.  you lose whole hunks of your gamut.  unless you do very careful, very specific renders, you can't address it in post because the information is just plain gone.

as far as i can tell, in most situations, you can postwork to get from GC to more accurate sRGB.  but gibberish workflow is just so off, you really can't.

oops.  x-post with bagginsbill.