Pity they don't have any servers <150ms away from me: http://wiki.voip.ms/article/Choosing_Server. I'm in Australia, so the SIP server really has to be in Sydney or Melbourne for it to work for me (~70ms RTT on ADSL). Someone from Perth can yell at me for being so Eastern-centric.
I haven't had a landline in about 4 years (known as "naked" ADSL - there's no dialtone on my copper line). I played with VOIP for quite a while but could never really get the quality I wanted. Then the mobile costs came down enough so I haven't looked since. Hangouts and Skype solved my international phone call problems, although I'm not entirely sure how they solved the echo/delay problems so well.
Edit: oh, right, this was an SMS specific article.
