I have been using a VS n grounding cables in all my cars for more than 3 years (branded, non branded & self made) n I can tell u that all that I have use works, some better than others depending on the capacitors used & in what combinations. Most self made VS consist of high capacity low discharge caps conbined with low capacity caps but with fast discharge rate, branded VS uses high capacity caps with high dscharge rate and they will normally add in a control n safety board to control the discharging rate & prevent overheating. I now use home made VS using good Japanese caps in various combination. My last one was built 30 months ago n it still works.

To me the most important issue here is whether we get what we pay for.
My two cents worth with no intention of pissing anybody