The website lists 3 CAFE reports. The Cafe foundation does good work. But if you read the reports, they are only suggesting that the benefits occur at circa 10,000ft and above with "very lean mixtures".
Lean mixtures are harder to ingnite, so I presume that the CDI unit shows a benefit when magnetos are on the brink of lean misfire.
Basically this is $3,500 to largely do the same as a $70 Jaycar CDI kit. I think I'd put the money into GAMI injectors instead.
Come in Jaba......