Camshaft lobe shape determines the DURATION that the valves are open/closed and how much they open (I believe this is what you meant by timing.

As for reliability and performance . . . the manufacturers have to take emmissions and gas mileage into account. Aftermarket doesn't.

Not an entirely free ride.

As for wear and tear, I have had more valve spring breakage with permormance cams but I don't know if this is due to the camshaft or the rest of the aftermarket parts (or the way the driver used them).

I don;t really consider the Delta or the CALMINI cams 'performance' camshafts. They both change the power/torque characteristics but do Performance and Isuzu really belong in the same sentence?

Steve G