Vortex ROK DVS - Is it Worth?

Hi folks,
I am a Kart enthusiast and I have a ROK GP engine. I am looking for a faster and fun new engine however it needs to be direct drive one. (No Shifter)
I have been looking for the ROK DVS which is a pre-OK engine, same revs by 16K rpm, exhaust valve, head , pistons. However there is really few info about it.
I would like to understand if this is a fast engine; level of maintanence, is the performance similar to OK? Is it worth?