Fascinating. We've had our P30 since about this time of the year in 2007. So that means we've had her on the hard, for winter storage, three times. In '07 and '08 we joined a club haulout and storage, so we did it ourselves, with guidance from fellow club members. Last winter we paid a yard. Six jackstands: A vee on the bow and three along each side. Took care to space them well and make sure the boat was balanced, with a slight tilt toward the stern for drainage. I don't recall how she was blocked under the keel for the previous two years, but she had one on the leading edge and one further back last winter. Nothing's ever oil-canned or collapsed.
First I've ever heard of the P30 being structurally inferior. I've always heard most Pearsons, the P30 included, were built like tanks. What I've always heard makes them unsuitable for off-shore use is the spade rudder.