If I do a search on ELL for have been I get 17K+ results. Have vs Have Been yields a more manageable 409 results. This is just for those specific words. ELL, however, is filled with similar results for all perfect/continuous tense situations.
Can we, as a group, agree on the most comprehensive answer to this question and then just direct all new questions to that answer? I've seen some really great answers over the past several years and can't believe that the amount effort that went into those answers is matched with every new answer. In other words, the twenty word answer I provide today is most likely inferior to the 1,800 word answer provided four years ago.