good question!
i'll start with - I have both and love both. you're going to like what you pick either way, and will probably eventually end up with both just like a lot of the rest of us.
fit and finish - chaparral
carry - once you get a low-profile clip (from benchmade, just ask), identical. without the BM low-rider clip, chaparral wins. personal preference for me.
ergonomics - I have big hands and prefer the chaparral, believe it or not. the choil/finger cutouts are excellently placed for a small knife. good on BM, exc on Chap
appearance - chaparral - classier looking knife, excellent little slicer that can readily handle other duties.
so for me, chaparral gets the nod, slightly in most categories. but I do love both.
pluses to the bm mini-grip - love the axis lock. both are easy one hand open and close, axis is easier than chaparral. flickable, even

customizability of the mini-grip is great. expensive, but great. I ended up getting an n680 sheepsfoot blade with spydie hole for saltwater use, olive green handles, silver hardware all around. looks very nice, excellent for saltwater boat usage, river fishing, etc.
I think the chaparral is a 'better' knife for the money, but both are excellent.