How long is the process to get an i360 ( vawa) approved?

Usually vawa cases range from 6-12 months. I don't understand your statement though about being on a "second prima facie." You mean you are extending your vawa case? Your prior spouse was not a US citizen and therefore you cannot file for adjustment yet since the priority date is not current is that it? But you can file for a work permit and travel document in the meantime. Getting the initial prima facie determination is the hardest. If you got that already the first time than no need to be frustrated and worried its just a matter of time.

There is no set timeline. However, as long as you receive the extension notice - Prima Facie notice - you at least are eligible for an EAD and you can get a driver's license.

Our office has several VAWA petitions pending. Our VAWA petitions used to be processed in about 6 months to a year depending upon requests for additional evidence. We did have one VAWA petition that took nearly 3 years to approve, but this case was an anomaly. We received multiple requests for evidence in that particular case, but we believe this was triggered by the husband withdrawing the immigrant visa petition claiming fraud. However, we have noticed a recent increase in processing times.
According to USCIS's website, the Vermont Service Center is processing VAWA petitions filed on or before June 5, 2011. This data is current as of November 30, 2012. I understand you frustration, but unfortunately there is not much that can be done unless the case falls outside the normal processing times and promptly respond to any requests for evidence.