BB1, I use India Ink for the wheels when I am not using a dark species because it stains deep and uniformly,  plus I'd rather pay $5 for a bottle of true black ink that will last me for a number of years rather than $23 for a pint can of GF.  Another consideration for me was the intensity  of the black hue.  The Onyx has more of a deep brown hue to it and no matter how many coats I'd use, it wasn't dark enough for me.   I have used regular stain in the past and just like the subtle effect I get with the ink.  It's a matter of preference and just something I have adopted.     Thanks to you and crowie for the comments.