Well, it's an old car for starts, so you'd expect things to go wrong. But, the things that have gone wrong nearly got me killed! Your brakes failing and going over the Cork/Kerry Mountains is no fun experience. In general, it's pretty hard on the brakes. I always have to get something done to them every few months when I have it in for a service.
Other than the brakes failing there has been nothing really serious that has gone wrong with it. Although that could change when I bring it in for a service tomorrow.
For me it's main plus point is that it is economical. On a full tank I get 500 miles plus and that's city miles. Insurance is cheaper, but Tax isn't. Same as a petrol car.
I didn't find any problem with the brakes of my Vectra. It's roomy in its class and is economical. However, the interior noise level and the disturbing suspension really made me feel uncomfortable.