"most providers typically took 48 hours to resolve faults that caused a total loss of service"
I switched to Zen from BT maybe 3 or 4 years ago. It was only a couple of months ago I actually had need to call Zen's customer services due to a loss of service. Was only kept waiting a few minutes, and the guy fixed the issue -while I was still on the phone-.
Compare this with my prior 12 or so months with BT. A service that repeatedly dropped connections, a call every 6 or 8 weeks to try and resolve some issue or other with wait times always in excess of 10 mins (most often longer), multiple engineer callouts, general denials of any issues etc etc...
No comparison really. But this is not the first time I've extolled the virtues of Zen on these forums :)