I have (Cox) cable and I love it. I average about 3 megabits, but I think my max is ~5 megabits. There are only a few downsides with cable. The upload is slow, and most likely if your cable TV goes out, so does your internet. Now with DSL, you get a pretty even ratio of Upload to Download (at least with Qwest/US West). I had DSL and got about a half meg each way (up and down). DSL is generally sent through your telephone lines, so I'm assuming if your phone goes out, so does your internet.
edit:: It may have been a busy speed test server, so that might be flawed. But if you notice your browsing is generally slow, then call your company up.