I'd been thinking about adding interrupter brake levers since I first saw them. Many times on the roughest dirt roads and technical trails I'd wished I had convenient brake levers when riding up and back on the tops of the bars. I've also wished for them when riding slowly, touring with slower riders. In both situations I want to sit up and look around.
Adding these will definitely limit my positions on the top of the bars. That had kept me from trying them. Overall, I hope they make this bike more versatile. I set them wider than the reinforced center section to add more light-mounting positions above the bar now that the levers and different cable routing take up space below it. I can easily fit four Planet Bike Beamers now. I could probably fit a fifth one under the bars on the right (bike right, not photo right). That's gettin' crazy.