As my WISP is Amobia and I get 4Mb down *and* up, which has opened the door to me up and fetching stuff straight from my office server as-and-when, I won't go near anyone's ADSL until that A is a WHOLE lot less a than it is now. And even then only maybe, my internet feed and network cabinet is now effectively lightning-safe, as compared with the surge that can come down the line and fry the modem/router. As for the high site going down: yes, that happened to me recently. As I happened to be at the office at the time, I called it in straight away and not only didn't get treated like an idiot (they must have the best tech support line I have ever met) but got it confirmed ...and my connection temporarily transferred to an alternate site for the duration.
Assume the usual "subject to" and YMMV, but that's where I stand (and try to get clients of mine where possible/relevant).