Well, I started over 6 months ago - when I took a voip.ms number to use with my nexus. The sign-up and ordering was very simple and I bought a number and we were up and running in 5 minutes flat.
I was extremely impressed with the quality, so I got a ObiHai OBi100 box and took another number to test if this can replace my landline.
People never noticed the switch ... the voice was crystal clear, and it was very cheap ($5/month approx) as opposed to the $36 my phone company charges for nothing. I finally ported my number over. The staff was very knowledgeable and extremely helpful.
I have 3 numbers with them presently. I am extremely happy with the overall service and I recommend them!