I am concidering going to Voice over IP, have you tried that? What do you think? Tomatovine has a very good deal at the moment.
I will be experimenting with it myself in the next year or so.
I heard that it has a tendency to drop-out at times, and you definitely need to have an alternate plan in place should you ever have the misfortune of needing to dial 911.
Yes, depending on your cable provider, it can drop out occasionally. Also, if the power goes out, VOIP goes out too, unlike conventional phones. Voice quality is at least as good as conventional. 911 goes to a local emergency number, but is supposed to be treated like regular 911 soon.