For example, a few weeks after I got the bike, I started breaking spokes on the rear wheel. Repeated trips to the bike shop finally had my mechanic rebuilding it from scratch. That's when he discovered that about 1/3 of the spokes on one side of the wheel were too long, and had never been brought up to tension. I replaced the rim, and the rebuilt wheel's been going strong, but that kind of thing is just plain sloppy.
Also, the rear drop-out spacing is too close together. This means I have to spread the bike frame at the back just to put the wheel back in after I've removed it. Aluminum is brittle. You can't bend aluminum the way you can bend steel, and so, this is an ongoing problem. (See this article for a simple explanation of brittleness and metal.)
I also found that anything labeled "CODA" meant "Crappy Offshore Dumped Accessories," and I've replaced all of these parts but the crank (though the CODA logo came right off the crank the first time I polished it).
Don't get me wrong, the bike's still going strong. I like its lateral stiffness, and while Cannondales have the reputation of being a harsh ride, this touring bike feels fine with a Terry Liberator men's saddle.
It's because the fit & finish of the Cannondale doesn't impress me that I'd never buy another.