1) DSL - speed varies with distance, however, your speed 'should' be consistant, once connected. i.e. sync rate locked at 3008/512. 2) Cable - high burst rates (i.e. maxed at 8/6Mbps/384 kbps), however nodes can get overloaded, especially during peak hours.
Since I perform remote access work, I need consistancy, and decent upload.