I replaced a set of Vittoria Rubino Pros on my training wheels with the Continental Grand Prix 4 season tires based on a recommendation from my team LBS. I've been riding the Rubino's and the Open Corsa CX's for some time and very happy with their performance and handling. I have been amazed at how close they come to the handling of a true tubular. I have used conti's many times in the past and never had a problem with them.
The short of it is after only 6 rides, I remove the ($100) Conti's from the bike as being virtually unsafe to use. I'm a moderately aggressive, but not insane, descender and nearly lost control at lest 4 times on two rides down the same 35-40 mph winding descent. I had to descend at ~10mph slower than I would normally ride this road on the Vittorias. The tires almost completely wash out at very modest lean angles or with very little disturbance - ie. small pebbles (not "rocks"😉. The feeling is very similar to riding through corners on a flat. I've unfortunately lost virtually all confidence in cornering - not a good thing for a crit racer. Tire pressures are 100-110psi as recommended. In addition, I can feel the tire sliding out through flat corners at modestly fast speeds (normal training ride speeds) and I find myself prepared to counter steer when I should be leaning more.
I'm curious if anyone else has ridden these tires and experienced better or similar performance. Is it me, the tire, a bad lot? I've sent conti an e-mail, but apparently they are not interested. I know the GP 4000 are popular, but these are presumably different than the 4000.