6.5 if you want half block and S-6 if you want a full body..
Both extremely nice and very similar still different enough to notice.. The half block designs are a different pump stroke than the full body designs.
I agree with testing what works for you.
I personally dig the full body designs I Think its hard beat the smooth pump stroke that you will find with them. You ever around a Greifer just ask and none of us mind letting you throw some rounds out.
Friends off field - Friends on the field - @ 10 seconds you become Nameless, Faceless and my Enemy.