IANAPilot but I would be shocked if canards improved rate of climb. As long as a plane can point its nose up at a given angle the rest is up to the engines to push you up that slope. Maybe if they reduced drag a lot but I would think an extra bit in the airstream would be more likely to increase drag. But maybe they are mope efficient than elevators? (total WAG)
I can see a canard maybe making a plane more maneuverable though.