The thing about nails is all about how you hit them. You can actually run straight over them while they stay flat and see no issues. But the smaller the sharp object, the more likely it's going to flip and penetrate the tire. When that happens, especially on a rear tire considering the weight it's bearing, relatively few things will stop it.

As far as Gatorskins, I run them on my roadie and have never flatted and a lot of the shoulders on roads near me have debris that penetrated tires like Michelin Pro 3s, etc. And as far as wear, nothing beats them. I have about 2,500 miles on my set now and they're nowhere near worn out. That was the limit on several other tires I tried, including "hard case" tires from Bontrager and the Maxxis Refuse.