Here's a wicked description I found from a seed site that sells Vortex, it's a description of my experience with the last V x BK:
"The Vortex buzz can be energizing and heart racing, but it can also be ripped under, curled under stupid stoned. This high has virtually no ceiling, so that the high keep climbing without a burnout point. When used lightly, this strain is a real pick-up for the senses, stoking creative juices and provoking thought. With heavier use, Vortex becomes mentally confusing and potentially disorienting. Even veterans can find themselves spinning and swirling in the vortex of its psychedelic influences."