Used to have SDSL, which I had for a great deal and was a great connection. Always solid, rarely (if ever) disco'd. Moved and had to switch to @home...disco'd all the time. @home and AT&T parted company, now it's AT&T's own system and my connections are stronger, hardly ever disco, and service has been capped at 1.5mb down (fine by me). Could be good, could suck for ya.
My only experience with digital cable is that the menus are slow, switching channels is slow, and it altogether sucks. Dish Network is cheaper for me, and muuuuch faster in the menu system & channel switching.
SOB