Reliability is one factor that should be considered heavily, as is flexibility. Forget about VoIP. Think of the market as divided into two. Dedicated Phone (Bell, Cablecos) is more reliable, but more expensive -- it's got its own path to the rest of the world. But you can't take it with you. Internet Phone (Primus et al) is more flexible, and cheaper -- you're paying for the Internet anyway, and it uses it to get to the PSTN cloud. But the engineering feat has to be much more impressive for you to get the same reliability. Maybe I'm a happy Sympatico customer and want to keep them as my ISP. You can -- regardless of who you choose as a Phone provider. With Internet Phone, you'll be running it on top of your Internet-over-DSL. With Dedicated Phone, it uses a separate wire pair inside the house, and even (if you mix Rogers and Bell) a separate path out of the house. Just about the whole world has called this VoIP vs POTS/PATS/TDM telephony. I'm beginning to see that's the wrong way to think about it.