I don't question your experience with poplar heartwood, Mel, but it just isn't available here as such. I have read elsewhere of old growth poplar being quite durable, and we have a meeting house in my town trimmed out with old growth white pine ca. 1890 which is going strong. I wouldn't bet $.010 on the same building built today with second growth material. Perhaps the same is true of today's poplar as opposed to the old material.