I kinda have a little thing according to size, most small .40 sized I use HS-425bb or eqivlant except pull-pull rudders, I user HS-645 or equivlant. Up to .60 sized I use HS-635 or 45's all around or equivlant digital. And anything bigger up to 35% I use HS-5645 except on rudder, I use HS-5995TG or equivlant digital and on 35% to 41% I usally use HS-5995 all around or equivlant digital. All used with 6v if possible.