Even though I mentioned putting the shiny side out and condensation in the same breath, they were separate thoughts, only related because they both have to do with the reflective surface. I realized after I posted that sentence, it could be construed that I'm trying to prevent condensation on the outside (which of course, wouldn't matter), which is why I edited my post (see above).
Ah, gotcha. Indeed, it does help with condensation in all but extreme cases. If there's anything there it's typically just a light film (noticeably less than Lunar Duo). I will say my 5x7 polycryo groundcloth covers most of the floorspace unlike some that use just a 3x6 piece. It normally has quite a bit of condensation on the underside of it, which I think helps. The times the condensation has been droplets on the LDPE were when temp dropped very quickly with a storm or I added my storm door so there wasn't much ventilation. Those occasions taught me that slipping my DriDucks jacket over the bottom of my bag works sort of like a bivy (and using a trash compactor bag instead is a bad idea