Sounds like you've got a good cheap solution there.

I remember once having to deal with an irate director of a company once who was going mad that all his staff couldn't work as his ADSL was down. He was complaining that even their backup ADSL wasn't working. No matter how I tried I couldn't get him to understand that is going to happen when someone opens up the box outside his business and steals a 200m length of cable, writing off the duct work (it collapsed when all the cable was pulled out) and taking down about 400 peoples phone lines. They worked 24/7 shifts for almost a week to get everyone back on, but that still wasn't good enough.

He had an office of 30 people all sharing 2 ADSL connections, they were some kind of insurance broker. The compo he got was just a few hundred pounds, he tried to invoice for a weeks lost revenue and costs, but with no SLA in place there is no chance of that sticking given the circumstances.

Diversity and redundancy in supply would always be the top of my list. I even have a (very simple) plan for my home business here should my FTTC go off. We can't get Virgin here, so I swapped my mobile service to 3 a couple of years ago so tethering is included as standard. Whilst much slower, I could manage with this connection and I have checked everything works should I need to use it. Sounds stupidly simple but I was always amazed by how little thought people gave to this on such a critical thing. I think 4G routers could become a really good idea in the future for backups, as we find out prices I might look at them for myself here.

Cheers

Cris