we have FIOS with the phone line because it's just a better value to get the triple play. I think tv + internet is already $35 + $50 anyway and we signed up for a promo for $70/mo. for all 3. It has battery backup for a few hours should the power go out, but we haven't had to use it in an emergency.
During 9/11 and the northeastern blackout a few years back, we had a copper line (before FIOS) and I plugged in an old phone that is powered just thru the phone line. Those are the way to go. Actually FIOS still gives the option of keeping a copper line, for a slightly higher monthly fee.
That's one of the main advantages I was trying to point out. During a power outage the cell towers will be overloaded and don't have the same guarantees for service without power. They are essentially useless with a wide scale power outage.
Your true hardline? Not a problem. I guess a good number of people don't realize you can plug a phone into your hardline and have service. If you don't have such a phone then, well...no phonecalls for you. So get one.
I will NEVER give up my landline and phone. In a power outage, your cell isn't going to work. And not to mention the quality.