If it keeps the weather out, I would be glad to be in it during a storm. It is small, so I would hope only three or four people would try to take shelter. If I had taken the side trail just to see the unique dome structure, I would be disappointed that there were so few panels. The fact that it is a geometric dome is probably not much of a structural advantage given the number of panels and certainly complicated the construction.
This is what I would have expected as a minimum, given the size:
http://www.cccoe.net/stars/graphics/Dome.jpg
On the other hand, it was built by a private individual, and beggars can't be choosers.