I've owned these in 32 and 35c variants. The 32c suffered three punctures. Once was a piece of rusty, bent metal about a centimetre long - I was surprised when that happened as they'd done a good few thousand miles by that point. One was unidentified resulting a small hole in the tube, the last is pictured - a four inch screw laying in the road went straight through it. It had to go in the bin after that.
The 35c only suffered one puncture. An unidentified object ripped clean through the side of it. All I know is the item was metal and hidden by leaves. It was rather annoying standing there trying to get the tyre off whilst cyclists (no doubt on cheaper, lighter tyres) went past. It was so damaged it had to be binned.
These tyres are pretty puncutre resistant - I did a lot of miles without problems but no air-filled tyre is going to be puncture proof. The marketing spiel about punctures being a thing of the past is optimistic at best - don't leave home without two spare tubes. However, I've no doubt you could do many thousands of miles without a puncture (which I did) - it's just down to luck.
The ride quality isn't good. The sold rubber 'smart guard' ring feels separate to the rest of the tyre so if you're going over a ridge or a bump somtimes you can feel it sort of fall to the side. The grip isn't great either in the wet. They're also very, very heavy.
I didn't find them that hard to fit. Bit of a pain getting the 35c on a deep rim but I've fitted much worse.
They're not bad tyres but I'm not sure I'd buy another. I've had excellent puncture resistance from other tyres such as Vittoria Radonneur City which are half the price and little over half the weight.