EVDRIVER said:
Rock hard tires also further decrease traction and stopping distance as well as lateral traction even further.
The correct answer is - it depends on your definition of "rock hard".
Stock tire pressures are usually way too low for optimal handling performance. Most people feel that pressures of 40 psi+ start getting into the range of "rock hard" as you feel lot more of the road at those pressures.
Braking performance is not affected much by tire pressures unless they are very low (less than 20 psi). At high tire pressures you'd have to be exceeding the pressure listed on the tire's sidewall to significantly affect braking distance (typically around 45-50 psi).
As far as cornering, higher tire pressures are preferred as well as it keeps the tire from folding over under lateral forces thus keeping more rubber on the road. If you go too far - yes - you'll also eventually reduce traction but again you'd have to be exceeding the pressures on the side wall (typically around 45-50 psi).
Coincidentally, once you've inflated your tires to 40 psi or so you typically hit the point of diminishing returns in terms of reducing rolling resistance - so there's not much point in going significantly higher, anyway.
Conclusion: Increasing tire pressure above the stock 32 psi to 40 psi+ will result in lower energy consumption, better handling and same braking performance at the expense of some ride quality.