So all in all, I prefer cable since it is the same price here. I too was concerned about the cable company service and reliability. However, they have made a lot of improvements over the last 10 years or so. I'm sure everything varies location to location.
There will, of course, be people who live in areas where the reverse is true but I work for a gaming company. We host thousands of players a day (we're the primary host of America's Army) and the general rule of thumb is: players pinging under 60ms are on DSL....players over 100ms are on cable or 56k.
Whenever you see someone spike up to 500ms or more it's usually followed by a "F*cking laggy cable" or "Cable R teh sux0rs!!!!!!!!!!!!!!!!!!!!!!!!" chat from the player.
In four years of admining, I've never once seen a DSL player say that. Although, as you indicated, DSL players will sometimes (very rarely) lose their connection.