={MAX(IF('IDT Data'!C:C='2STAR'!C2,IF('IDT Data'!I:I="P",'IDT Data'!F:F)),IF('IDT Data'!C:C='2STAR'!C2,IF('IDT Data'!I:I="R",'IDT Data'!F:F)))}

Above formula does a nice job of pulling the lastest date a person was piad, but is there a way to not use an ARRAY formula, as it is totally locking up excel anytime you change something on the spreadsheet.