Maybe first try replacing the brake pads. Also, make sure that the pads are properly aligned AND centered (contacting the rim at the exact same time). If centering is off the brakes won't feel abrupt at all since one side has to actually push the rim to the other side before the second one will contact it...makes for horrible feeling brake action. Also, if you're using the stock pads on the tektros, I've read multiple reviews for poor performance based on the pads. Many who replace the pads with something quality (Koolstop, Swiss stop, even shimano) notice a huge improvement and are happy sticking with the calipers. Caliper design is fairly standard (with only design flair differences, and theoretical "stiffness" differences) and because of this similarity can work just as well as others if compared using the same brake pad compound. Just a thought.

-Jeremy