I have been a certified in the use of the CVSA for over 10 years. I recently retired but prior to that I was the primary on background investigations for truth verification. Prior to being certified for CVSA we sent our candidates to an outside firm for polygraph exams. Once certified I conducted the CVSA on many candidates over the years. We were able to weed out several due to issues found during the CVSA exam that never showed up in the background investigator's report. The CVSA is easy to use and causes less stress on the examinee. I know, I've had both polygraph and CVSA conducted on me.

Overall the process for certification is a lot less time consuming and using the CVSA requires less equipment, computer and microphone. It can be conducted anywhere and almost at a minute's notice. As with any interview/interrogation, a lot of the success depends on the examiner also. 

One of my last CVSA tests I conducted resulted in negative findings on a candidate that we had thought was a top prospect, a former police officer from another agency who was trying to get back into policing after leaving to start a business. He failed the test. Since he was such a "top" candidate, we conducted another test with a different CVSA examiner. He failed that test also. Command was concerned due to his previous law enforcement experience. He was sent to an outside polygraph examiner and failed that test also, which just showed that the CVSA is just as accurate, if not more, than the polygraph exam. 

In my experience, the CVSA is a good tool, accurate, and easier to use for both background testing and criminal investigations. I know agencies that use both for various reasons and settings. The CVSA is just so convenient and easy to use, less stress on the examinee which I feel makes the testing more accurate because the stress caused by non-truthful answers shows up so much more.