NHTSA's crash-test data for 2005 midsize and large SUVs tends to support Porsche's claim. As you can see in the chart below, in general, unibody SUVs are indeed safer than their body-on-frame counterparts. They score considerably better in front crash and rollover tests, and score only slightly lower in side impact tests. It should be noted, however, that many of the body-on-frame SUVs tested were older in design than most of the unibody SUVs. Perhaps with the application of newer technology, body-on-frame SUVs will be safer in the future.
NHTSA Crash Test Scores
