I've been a happy customer of a Tepui Kukenam for about 18 months now, and have around 150 nights in the tent. For the most part is has held up great. It has been on the roof for mostly the whole time, on quite a few very rough wheeling trips without incident in every type of weather. Here are my complaints, although they are few:
1. Condensation under the mattress is by far the most annoying part of the tent. I use my tent mostly in winter so it's a real hassle. I'll be getting the hypervent material posted above (Thanks Dennx for the link).
2. I've gone through 3 ladders now. On the first ladder, the clips that keep the ladder from collapsing down did not work. As soon as I put my whole weight in the tent, the ladder would collapse down. The other two ladders broke where the ladder mounts meet the ladder. Tepui sent me all new ladders each time at no cost.
3. The zipper is separating from the door in one spot, for about 4 inches. Probably an easy fix with a basic sewing kit, and definitely just from normal wear.
4. I've had problems with the cover zipper separating from the fabric. I keep 2 pillows and a down comforter up in the tent when it's packed up, probably what has caused it. And the zipper itself broke, here's a pic. Tepui sent me a new cover zipper free of charge after this happened.
In all, this has been a great tent for the money, and has performed fantastically. I'd recommend Tepui for anyone not looking to spend $1500+ on a tent.
And since everyone likes pics: