Henry,

I only had the really bad stretch on one night. Ordinarily it worked fairly well, but one night where it cooled down a good deal, steadily through the night, while raining the entire time, it continued to stretch throughout the night.

I verified that the stakes had not moved (fully sunk into firm ground), and I don't believe the guylines budged, as there was zero wind that night, and they've never slipped before. Generally the opposite is true, they hold the cordage so tight, they're sometimes difficult to move. My trekking pole is solid (1-piece) so no slippage there, and I don't believe the pole would have been able to sink into the ground at the location I camped, it was very firm ground.

Like I said, I've used the thing quite a few times since I got it this spring (purchased second-hand), and have really liked it every other time, (no other instances of sustained rains). I was initially hesitant about silnylon stretch, but TarpTents are so highly regarded, I dismissed my worries. This particular night seems like sort of the "perfect storm" of sorts, what with the rain and cooling, and I was miserable.

I appreciate your offer to help, and as an engineer, I realize that PAI (people are idiots) is always in play, but I genuinely don't believe this incidence was due to user error.
If, however, it was, and I did something wrong, then I'm probably going to screw up in the same manner in the future, to similar results. I'd rather give the tent to a new home, since there are plenty of people who would love to have it.

Like I said before, the attention to small details/features in TarpTent's offerings really impresses me (in all of the TT's I've seen, not just my contrail), but I just don't like silnylon. Perhaps I'm being unreasonable, and will regret this decision down the road, but that's where I'm at right now.