If you use USB your DAC receives the data asynchronously, that is to say that your DAC re-clocks the data, which voids any benefits of using a Word Clock sync, I have experimented with different outputs from the W20 and only the AES 110ohm & the SPDIF outputs are affected by the word clock sync option. As I want to be able to take advantage of high res files it means using the USB output anyway. So the word clock sync is of no value. MSB offer a Pro USB module http://www.msbtechnology.com/accessories/prousb/ which effectively reduces any noise out of the USB output by converting the data to fibre.
SGM who make the Taiko Extreme previously built the SGM 2015 server, which used Roon Server to output data to HQPlayer and upsample everything to DSD 256 or DSD 512 whichever format your DAC could accept.
However honestly, ultimately the PCM bit depth, even if it’s just 16 bits, gives a better dynamic range then DSD. I have been quite a fan of DSD for a long time, the first SGM servers where designed to upsample everything to high DSD rates. This is a very valid approach for “medium range” systems, but people buying the Extreme typically own top flight systems, with upper echelon DACs, and those do just perform better with PCM if the server noise floor is vanishing low. DSD256 or DSD 512 sounds a bit less precise / smoother, which is just what the format sounds like.
The new Taiko Extreme does not upsample and does not use any internal clocks as typical high end DAC's re-clock the data anyway. It does play bit perfect as I have verified using MSB test files. The use of internal clocks cause noise which is the antithesis of the way the Taiko Extreme was designed. Rather than disabling services and removing Windows components after installation the OEM version of Windows installed on the Taiko Extreme is massively cut down so that anything unnecessary is not installed in the first place. The playback chain is Roon routed through JPlay.
I was initially skeptical of the Taiko Extreme, I was about to upgrade to the W20SE and I have always been very happy with my W20 and raised the same questions you have! I held off for about 3 months whilst I read every page on the WBF site about the Taiko Extreme.
https://www.whatsbestforum.com/threads/taiko-audio-sgm-extreme-the-crème-de-la-crème.27433/ There is no doubt that it is beautifully built however it is considerably more expensive than the W20 or the W20SE. Here in Australia the W20SE retails for $34,000, the Taiko Extreme for $49,000 before options.
I started to hear 1st hand reports from friends who had listened and done the comparison for themselves in Singapore, Hong Kong and Korea and it seemed to me that I had to satisfy myself. I started a dialog with the designers - Emile Bok and his partner and asked pretty much every question I could think of. Frankly I didn't want it to sound better than the W20 or W20SE. Eventually a few weeks ago I was loaned one by the new Australian Distributor - Nirvana Sound. The Extreme weighs 42KG and is even better built in the flesh. However it was the sound that drew my undivided attention, this was not just an upgrade over the Aurenders it represented a Sea change in digital sound. Suddenly I was listening to what I thought were very familiar tracks and they sounded very close to 1/2 inch tape masters and certainly what I have experienced from top flight Analog Turntables, in some cases superior to the best of Vinyl, the variances I was hearing were mostly due to the original recording quality.
In summary - I have never heard digital sound anything remotely approaching the sound I was hearing from the Taiko Extreme.
I take delivery of mine in a few weeks time. It would be a good idea to start a new thread on these forums where we can hopefully invite the designers to respond to our questions.