Pros and cons of increasing camshaft sizes?

Bigger cams gain horsepower and/or torque, but sacrifice fuel economy.

Big cams often lose torque or move the torque curve up so much that you lose bottom end torque where you need it. If you never haul a load or tow then it should not matter to you. With careful selection of parts you should be able to increase both torque and HP but that would mean head work and other things in addition to the cam.