Matt's kit clearly works, the VWCup runners kits clearly work. Maybe it's slightly different and they changed the road version, I don't know? And DS2500s are fine until you overheat them, then they melt like butter and you'll have no pads. Simples. They're not really a track pad, they certainly are not a race pad.
It isn't fundamentally a bad road kit, the big pot leading is wrong and a bolted disc isn't ideal, but for 90% of people (pending the pot issues) it'll be perfect.
For the other 10%, you wanna play racecars, you've gotta pay racecar money. Just buy the best... look at any decent race/rally series, they're not running "pretenders", brakes win or lose races. AP, Alcon or Brembo at a push, as their consumables are vulgarly priced.
The thing is, most people can't justify AP/Alcon/Brembo money - which is where a good VWR kit will come in. I hope they get the issues sorted and the 4-pot is a good 'un.