I use both Vonage and Skype when travelling abroad. If I have a fast connection I prefer to use Vonage (the softphone), but over slower connections Skype works better. I tried using Skype over a dial up, but it was pretty choppy. Most of my calls are made using the Wifi connection on my portable, and I use my t-mobile hotspot account. Generally my experiences have been favorable, and you can't beat the price!

I use a headset, so I can't help you with the handset issue.

Hope this helps.