I've been using Alcazar for about 18 months, mostly as a secondary source for termination. I do have a handful of DIDs with them but moved most of them to my other provider because the monthly DID cost was on the high side. Their termination rates are pretty good and their support is outstanding. John Chisca is a really good guy and whether you have 10,000 lines or 1, he answers your calls and returns them too.