You need to run them in to harden the lobes, and make sure they have a good coating of either cam lube or, preferably, graphogen. This is regardless of whether they are new or re-profiled: as the old hardened surface will have been removed by the re-profiling.
the high idle is because there is more stress on the lobes at low engine speeds
more gen here - http://www.v8engines.com/Acrobat/cam-installation.PDF