We have had very few problems (just one brief service interruption when a whole area went down) in almost a year of service with Verizon. Also, our DSL at home leaves the cable modem at my office in the dust.
All I can tell you is that I work at home and in an office. I have DSL at home, Comcast cable modem at the office. Cable modem is down at least part of every single day, and is often very slow. I have no such problems with my DSL.