I cut a big gash in a tire sidewall about two years ago, and the nearest bike shop did not have ultra gatorskins. Since it was my commuter bike anyway, I went ahead and got a Bontrager Race Lite Harcdase. They are slightly heavier than the gatorskins, but I actually found that they were also much less prone to punctures than ultra gatoskins or armadillos (goathead thorns are very bad here). I was sold, and started buying them as other tires wore out ever since.
Until this year...when my county fell in love with extra rough-grained chip-n-seal. Chip-n-seal has always been popular here, but they used to include sand or crushed stone in the aggregate mix. Now, they just use the bigger stuff that is mostly in the size range of dried lentils and small-grained rice.
That type of chip-n-seal tears the rubber right off the outside of my rear Bontrager Race Lite Hardcase tires. I've had a couple of tires that started falling apart on roads with that rougher chip-n-seal. You can see big patches of green kevlar belt along the center of the tire, and the loose rubber slaps my brake calipers. Scary stuff.
So...I'm back to the ultra gatorskins. Maybe I should order some Schwalbe marathons next time?