K, I hope I'm not repeating anyone here, lol, cuz I clicked on comment without reading what had already been said, but here's my rule.

Past perfect tense (have, had, has been, blah, blah) is really awkward to read and write. If you're going to have a passage about something that happened in the past, usually just the first sentence or two is enough of a transition in past perfect tense, and then I'd use straight past. But, of course, I'm saying this without knowing the context, so I could be waaaay off base.