Hey -
I did the same thing you are doing right now and had Vonage for a while. Personally, I did not like it. I could hear fine through the receiver, but my friends and family all complained that they could barely hear me and that there was some kind of noise on the line.
Now, I just have my cell phone and just a separate Panasonic phone which uses blue tooth to sync to my cell phone. So, I have two receivers at the house (one in my room and one in the kitchen). It is synced to two cell phones, so if one of those two cell phones is in the house, that phone will work as well. If one of those two cell phones is not in the house, then it doesn't work. But, the calls go to our cell phones. So, we are fine with it.
The only reason that I wanted to keep a land line was to insure that a phone was accessible when we had a babysitter. But, now, ALL the babysitters show up with their own cell phone. Plus, we leave one of our cell phones at the house when the babysitter comes so that the house phone does work.
Oh, and you don't lose service when the power goes out - which was one of my beefs with Vonage.
http://www.amazon.com/gp/product/B0036D9YKA/ref=pd_lpo_k2...
-L.