Had Vonage for a while - call quality was generally good. Price was right. I wasn't using it too much so ended up cancelling the service.
At the moment my wife and I use cell phones exclusively.
Polar Boy - While I feel for any worker in a crunch, the phone companies have worked themselves into a poor situation. Mammoth infrastructure that's aging rapidly will have trouble competing with near-universal coverage from cell phones with easily-upgraded equipment. The only saving grace of POTS is that it will work for a while when the power is out, unless a wire is down.
Sadly, the telcos in my area haven't been known for their customer service or ethical business practices (slamming, etc), and they are paying the price in the long run.