I've talked with Tony about the SX700-LPT and I have high hopes. It sounds like the fan control is sophisticated enough to really keep the fan off under low to moderate loads.
Forgive me if I don't take his word for it until there's a physical product that's both been reviewed by a serious site and has been in consumers hands. I greatly appreciate his transparency and communication with the public, but he's enthusiastic about Silverstone products to a fault. On all the Silverstone products I've owned, QC has always been an issue. It didn't matter if it was a case, a fan, a cable, or a PSU. What they envision and what becomes reality through mass production doesn't typically align.
TL;DR - I'd rather take the cynical approach and be pleasantly surprised than the other way around