i think that d5 is obviously better for black. black is a pawn up and looks to challenge white's bishop (while defending his knight at the same time).

so, Bxc3 would be (for black) considered a mistake, black would lose its advantage. Nxc3 is also a mistake, since taking a pawn exposes the black king and allows white to take advantage.

if you are white, you would hope for Bxc3 ... :) ... but black wouldn't play the variation you're proposing.

just a personal thing, but 3D pieces are ugly for analysis. lol

i'm a novice, so all that is just my $0.02