My tent zipper failed completely during a downpour in the Adirondacks last fall.
I was stuck inside a flooded vestibule for two hours before I could rig a tarp over the door with paracord, so what's the most durable tent brand you've actually tested in heavy rain?
My old MSR Hubba Hubba held up for a full week of rain on the West Coast Trail. The zipper gave out on year three, but the fly and floor never leaked a drop. I've seen Hillebergs fail too, usually from seam tape peeling off after a few seasons. Brand matters less than checking the waterproof rating and doing your own seam sealing. A good repair kit with ten feet of duct tape is more important than any label.