If you scoure the case threads, there is one report of a Spigen Neo Hybrid Metal case deforming around the bottom of the iPhone. That user said we would try a PC version but I haven't seen if he commented on it.
All these Spigen cases are just TPU with a PC or Aluminum bumper. They won't add structural rigidity, that would require a thick, hard shell case that would be rather bulky, like a Pelican or Otterbox.
I just bought a few cheap cases of ebay figuring that in a few months someone will come out with a truly rigid case designed to prevent bending.