I cant comment on the s-tac,
I have 2 s-iii's, one with the moa-2, the other a mildot.
both are 8-32-56, of the 2 I prefer the moa-2 reticle better for target shooting, the crosshairs do not obscure the target, and the 2 moa hashmarks are easier for me to split than a mildot. but I'm not ready to give up on the mildot just yet either as both the s iii's have good glass.