The tail IS a little thin. Mine, built box-stock, no hangar rash, violent maneuvering, or crashes was drooping after the first flight.

First, I tried to stiffen the tail with some fiber tape. That didn't work. I ended up cutting a slot out of each side, and installing a bamboo skewer spar. After that, the tail was very solid and worked well, until I crashed it and broke the skewer where it entered the fuselage.

It's now since been repaired, and is up for auction on Ebay if anyone is interested