We have a 35 ft k/c boat and there is a substantial enough difference pointing ability and also righting moment to use it in winds over 12 knots, especially on the windward legs.
Our draft is 4'6 witout and 7.5 with. Without the centerboard down we would reef at 15-16 knots ( no gusts), with it down we can remain with fuull sails and no terrible weather helm till 20 ( no gusts). Our pointing ability is 4 degerees higher also
Also the drag of the centerboard will depend on its thickness and shape. Ours is quite heavy (Laminate over metal)( my wife once dropped the line
when deploying it and the boat shuddered when it swung down into place. It is also very tapered with a very thin leading edge to reduce its drag.
We use ours quite frequently to gain an advantage on windward legs and often can sail inside ( point higher) many boats because of it ( not the only reason). It is on our checklist when entering shallower waters to raise it also.
We deploy it every time out to at least clear the trunk of inwanted critters so it doesnt get frozen into place through lack of use.
Dont get rid of it and learn how to use it to your advantage. Big differnece in useage from a small sailboat using it for its keel.