This is just my personal experience...... I had DSL and it wasn't too bad. Not as fast as I would have liked, but it was OK (I was at the farthest point from the central station, so that made my connection be not all it could be. When I moved about a year ago I was too far away for DSL and had to get cable. It has been great. It doesn't go out as often as my DSL (Twice in a year, compared to about once a month with my DSL). The tech support is better, and my download speeds tripled. As for security issues, the first thing I did was go out and buy a router to compliment my anti-hacker software. I wouldn't run cable without it.
Anyway, that's my experience. I know it varies from person to person and location to location.