I'm using not only the free but the pro version. Vark worked me thru the screens on Skype, looked into detailed logs and figured out problems quickly with responsible follow-up and timely updates. His response is unlike common tech companies which are usually short lines, but explanation in full what's going on and with clear instructions what I should do and how long I am expected to see the result. And what's amazing is, promise is always delivered.
If there were the sixth star, I'd have given it to this plugin.