Just got the Yokohama C.Drives fitted. Damn they are silent! I could not pick up any tyre roar except at very low speeds of 10-20km/h. Handling-wise, the car does not lose grip and slide out anymore, but the initial turn-in with the Astra has understeer. After the short amount of understeer, the car goes back neutral again. I'm not sure if it is the suspension or whether I am expecting too much out of the Astra after driving my Euro for a long while. Roundabouts that I usually take at speeds which are comfortable without body roll suddenly induce understeer and bodyroll. Noise-wise, I would dump my SP 2050m tyres for the C.Drives. Handling-wise, I'll have to find someone who has tried it or just bite the bullet and go for them once my Dunlops wear out.
Edit: Drove more with the tyres, and now it does not have the initial understeer. It was the rubber needing to be scrubbed. For now, I can attain similar speeds to the Euro, but with tyre squeal. Eventhough it's squealing, there is still more than enough grip available as I am not losing grip eventhough I am accelerating mid corner. These tyres are good!