Jeff,
A small thing to note that I ran into with the Rainbow, is that the cross strut at the top is sheathed in non-siliconized nylon. I found that this collected water and if rained on enough, easily seeps thru and readily drips down inside the tent.
I am not sure if this is the best method to fix this, but I just ran a layer of seam sealer all accross that material on the inside. Now my Rainbow can withstand my testing of blasting it with the garden hose without a drop getting through.