Choose them and don't look back
Their product just works. No drama. No downtime. It just works exactly as advertised which is what we and our clients want from an IVR system. Their service is amazing as well and we are able to get the support we need when we need it. Shout out to [SENSITIVE CONTENT HIDDEN]!
We like it all. We preferred to use the "PlumDev" where we build our own VoiceXML so we have ultimate flexibility on the workflow.