FAA rules are contradictory, since both actual PIC time and "handling" time can be logged as PIC time, depending on which clause you read. I take the conservative approach, and log PIC time only when I am the designated PIC, and log SIC time when I am the handling pilot when another captain is designated PIC.
Unless you're trying to build time for an ATPL, it doesn't really matter. Airlines specifying PIC thresholds for hiring purposes are "looking" for PIC time that is actual "Command" time -- the designated PIC for the flight.