The big thing about UASP for USB3 is for SSDs. With UASP you also get NCQ (Native Command Queuing), so 4K random performance gets a big boost in performance.
I would reckon you could run a UASP connected SSD over USB3 for an OS, and would be hard pressed to tell the difference from an SSD connected to SATA.
@JR, does that Silverstone enclosure require a firmware update to support UASP, or does it support it out of the box?
I have one of those enclosures arriving soon, via Scan computers.