between the two dot is my preference. fine cross hairs have a tendancy to wash out in certain conditions low light or tired eye. i have 4 different recticles 1/8 dot Weaver fine cross hairs B&L NP-R2 Nightforce and army mil dot B&L. NP-R2 and mil first then dot cross hairs last.
As an aside the weaver dot has cross hairs leading up to the dot. stay with 1/8 size over 1/4...1/4 will block too much of the target at greater distances.
Trevor