I wrote a review for Continental Ultra Gatorskin 700x28c's in Feb. 2011. I had bought those tires for my old bike (Steel Performance - 21 speed). I was really pleased with their performance - over 2,500 miles, no flats. Well, I was recently able to upgrade to a new bike (Specialized Roubaix). It seems like there are usually two things that most bike companies do not invest any money in when it comes outfitting new bikes - Tubes/Tires & Seats. I got lucky with the seat, it is fairly comfortable but the tires were another matter. Within the first 200 miles I had already had two flats. I asked the bike shop where I bought the bike for advice. They said to try something called "Caffe Latex" (btw - Caffe is not misspelled, it is an Italian product). I found it to be pretty worthless, as I had another flat within a week.
That is when I decided to "Go with What You Know". Having such good luck with the Ultra Gatorskins, I searched again for the same tire. That is when I happened on these Gator Hardshell tires. These were advertised to be Ultra Gatorskins taken to the next level of protection. I didn't hesitate, I bought a set of these and puncture resistant tubes (Michelin Airstop). SO glad I did, over 500 miles so far - NO flats! This is not a cheap way to go. But the peace of mind I have, that every time I walk out to get on my bike and knowing that my tires will still have air in them is next to priceless.
5/1/2013 - Quick update. Just changed out these tires. Managed to get 2,700 miles out of them with just two flats. First, was a really large nail. It wouldn't have mattered what the tire was made of, it wouldn't have stopped this nail. Second was a pinch flat, again not the tire's fault. I rotated the tires approximately ever 500 miles. They were still holding air but some of the thread was starting to show through. Great tire, still recommend them.