I'm one of those guys who keeps buying Continentals thinking that the last set(s) must have been flukes.
Every set seems to get hard and noisy quickly. The tread last fine, but the traction is long gone.
There are a set of top of the line Contis on the M Roadster I just bought. Under 10,000 miles on them, about 4 years old and always inside. Hard as a rock... zero wet traction, noisy and rough riding.
The only Conti's I've had tha were the least bit impressive are the snows on my wife's E30... and frankly they can't hold a candle to the Hakka 2's they replaced (though their dry pavement performance is superior)
I've yet to be disappointed in a set of Kumhos... replaced Pilots on my last M3 with them and a set will likely go on the Roadster... have used Kumho's (high performance, all seasons, and dedicated snows) on everything from my father-in law's CRV to my former '67 Mercedes 250SE to a Northstar Allante to my kid's Capri.
Maybe not the best tire in the world, but once you factor in the price they are hard to beat.
Bill