Well, it happened again. Here were the conditions:
It rained constantly all day and all night last night. I inflated my XLite with an instaflator, but obviously conditions were quite humid. (Prior to last night, the pad had been inflated once by mouth but stayed upstairs, and I never observed any condensation before rolling it up yesterday morning.) I woke up this morning, and as I was deflating my pad, I could see a lot of condensation inside. I laid everything flat and took a good look at the aluminized coating before rolling it up, and it looked pristine.
Then, as I folded it in thirds, I actually saw the aluminization wearing off on the edges where the majority of the condensation was. I got home and took this picture.
Before that, two weeks ago, I took my wife's XLite Women's out in similar conditions (to check out the higher R-value); though, it rained far less when we set up camp, and I didn't see much condensation. Seeing this pad, I decided to check it as well, and it has just a hair of delamination at the top.
Conclusions: (1) It's not as bad as last time (maybe the instaflator helped?). But I'm sure repeated use in wet conditions will continue the degradation. The wet season is about to end around here, but it will be back by the end of September, and it is something I can count on. Condensation will likely be present with any pad I use (all minimal and manageable), and the XLite appears to have issues with that.
(2) Damn if the pad isn't comfortable! I sleep really well on a NeoAir--and the horizontal baffles really cradle my body well. The collapse of the sidewall actually works better with my broad shoulders (too broad for the large, actually) than any other pad I've slept on.
(3) It's not clear how much the coating actually helps. I don't like watching the pad fall apart before my eyes, but that may not impact its performance much. Given the tests BPL did on the earlier generation NeoAir in the Sleeping Pad State of the Market, the R-value may come from the baffles alone, and I can reasonably expect the stated R-value without an aluminum coating.
What's not clear is what I should do about this going forward. To keep the pad that clearly has some issues or search for a different solution? Any thoughts?