I’ve been riding Continental Gatorskins since someone at Penn State recommended them to me in 2006. Since then, I’ve logged 2.5 seasons in all sorts of conditions, and have only had one flat (a 2-3 inch piece of glass which embedded itself in the tire over a couple of miles).
These ride much more gently than the Specialized Armadillos I was riding before - they don’t feel like race tires (not terribly supple), but you can pump them to 120 psi, they don’t flat, and it’s not like riding on bare rims (ala Specialized). They also wear quite well - about 20-30% longer than other tires I’ve used that were designed for training. Only Armadillos last longer, of the tires I’ve tried.
They’re not super cheap, but the money you save on tubes and the convenience of not having to change/throw away tires because of flats is well worth it to me.
The only downsides that I run into - they’re not light (but they’re training tires - do you really care?), and they don’t have super grip. I don’t feel nearly as safe in hard corners (especially in the wet) as I do with Michelin Pro Race tires or other races tires. This is to be expected, since Gatorskins are made from harder rubber, but still, it’s something to watch out for.
I’m going to try Schwalbe Durano and Durano Plus tires next - we’ll see if they match up.