I've looked into Vonage.
We have used Vonage for about a decade. No complaints.
Of the various land line alternatives (magic jack, vonage, etc.) the one with the highest rating from Consumer Reports is Ooma. It’s also dirt cheap. Hate their bizarre commercials, though.
Being the old fogeys that we are, we thought about ditching our land line, but just can’t bring ourselves to do it. If you do, make sure your cell phones are charged up if you think there might be long power outage coming your way.
I agree with the other Freeper who said you also have to remember to take your cell phone with you from room to room. You won’t hear it all over the house the way you would a regular phone.