We dont. But have you read the information on his site?
"If you have a PID, but dosing the basket incorrect, you better have no PID."
Serious? Youre telling me that if your dosing is wrong youre going to get better results from 20 deg temperature fluctuation than +/- 1 degree? Come on.
"Quality is 10 times better then all others."
And that would be why theyre about as cheap as all others? How exactly is that statement quantified anyway?
Finally there are photos of ugly looking holes that are apparently made by "All other brands, name brands, and after market as OEMs". Not sure how VST came to be included in that list but I guess as a manufacturer other than Rancilio thats what hes saying; and VSTs basket certainly look nothing like that.
Id be interested in hearing from someone who has tried them, but for $10 I think you have to question what youre getting; and given theyve got so many other facts wrong Id question the accuracy of their claims. I know for a fact some who are hopping on the precision basket bandwagon are doing nothing but machining the bottom of a regular basket to make it look good (and thinner and weaker in the process).
Of course no matter what pretty stuff they turn out, unless these guys are scanning each basket to ensure uniform hole sizes (and given VSTs process is patented I doubt it) there are always going to be variations within each basket which will lead to unpredictable performance.