about 50% of the flats I tended to were Corsa Speeds.
Everything I have read has said the same thing and friends personal experience mirrored that, but damn if I didn't get a lot of miles out of mine. Like I said, I might be an outlier in terms of tire durability or really, really lucky. I should go play the lotto...
I'm n=2. I've used Corsa Speed for TT, RR, criterium, and non-wood track for years now, and they've been just fine.
I can only remember one flat off-hand. That was a pinch flat in a 100-mile TT. (tubeless pinch flat, no less, which was a feat).
Does that make it a durable tyre? Surely what matters is what others have experienced. If someone asks you what your thoughts on the Corsa Speed were you would mention your experience, but surely add that many other people had had issues with Corsa Speeds. If I had never had any problems with my Corsa Speeds I would still mention to people that plenty of others had had problems. I don't get why people recommend these tyres based on their own individual experiences.
That said, these tyres were never designed for triathlon or long road races on sub standard roads. You only have to pick one up and compare it to a Conti Competition to see they are a completely different tyre, with a different purpose. Vittoria also do state on their website these tyres are only fit for short TTs and are their least durable tyre (bar the track tyres). Hence the reason these tyres are only used in the TDF for the TT stage. So it's unfair for me to say they are a shit tyre because I flatted a few times during Ironman races. Vittoria would never recommend them for an Ironman or even a 70.3. I have no idea how people can ride these for multiple seasons and not get flats, they are wafer thin.
In 8 years of racing I've had 7 flats, 3 flats in the first 2 years on Vittoria Rubin Pros, 2 of those were as I came in to T2 so was all good, 3 flats on Corsa Speeds in 1.5 seasons (I ditched them halfway through a season) and 1 flat on Continental Attacks. I'm now on Conti Attacks for my training wheels (2 years without a flat, shit roads) and Conti Comps for racing, no flats. I actually have 3 Corsa Speeds sitting in my garage and for shits and giggles was thinking about putting them on my training wheels to see how long they last. (tubs).