I am aware of Sheldon Brown's website and his recommendations. In all reality, probably the tire would hold 50PSI, but is simply does not give me confidence to descend at 30+ mph on a busy road while keeping up with the traffic. If the tire exploded in such circumstances, it would be hard to get out of that alive, and I have decided I am not willing to risk it.

I have been looking at Schwalbe CX Comp semi slick as a front tire replacement. My priorities are dry and wet grip, low rolling resistance and satisfactory resistance to flats. Would that tire fit the bill? And it is 50-559 size.