Amended Review: downside
I forgot to mention two negatives.
One is that the poles fit into grommet-like slots which aren't adequate, and if you let the pole slip out, it can easily make a hole in the floor of the tent. My tent is patched in two places from such occurrences.
When it is very wet, and you open the door, water pours into the tent. It's best to use the vestibule in very rainy climes. (you set up the tent from inside, so that's a big plus in rain!)