DSL is really dependent on your location in relation to the little ubiquitous brick phone relay buildings you see enclosed in chain link fences somewhere in your neighborhood. The advertised speeds are full of it - your location in relation to the phone relay is the real determining factor. I'm running one server on DSL that is in walking distance from a service block, and it screams faster than T1 even tho its supposedly only 768k.

Cable service drops as more people hop on. So does DSL, but if your first in line, its like water faucets - the first one in a series flows more water. Cable divides mathematically by the number of people on. Your position on the wire doesnt matter, when it slows everyone slows.

You can also get big degradations in cable due to your wiring scheme from the drop to your server. Is it a long wire run?