I just wanted to chime in here as I said I would provide an update on the W4S uLink and it's impact on the Rega Dac.
I'll probably post a full review of both components in the Headgear section but it's worth noting that during blind listening I was able to spot the W4S uLink everytime.
It isn't exactly revolutionary, but it is an audible improvement over the USB implementation from the Rega.
I will say that I do not care for the uLink with Wyred 4 Sound's own proprietary ASIO driver. It actually was about even with the USB implementation from Rega, but I did like the uLink in WASAPI quite a bit. In WASAPI with the uLink there was an apparent added dose of richness, timbre and overall life and bounce to the music.
The USB out of the Rega does sound very good... damn near outstanding.... especially considering it is a "GASP!" adaptive mode USB!
But when you have the uLink in the chain running WASAPI and then pull it out and go direct through USB you can hear the music flatten out a bit... Some of the exuberance and life is sucked out, everything seems like it is compressed just a bit.... Colors are grey'd out and music is just a bit less enjoyable.
I'll do a proper review when I have time.... In the midst of getting a proposal out the door at work... but the short answer is yes. The uLink does give you some improvement... $300 worth? That is relative to the consumer... to me it's noticeable enough that I don't have any buyers remorse with the uLink. It's staying.