Not sure the point of baseless comments like this. I will take your money if you're serious
Back on topic, I owned an S10, now own an X100L and have a W20 in my system at the moment for a couple of weeks (unfortunately not mine). The USB out on the X100 is based on the W20's USB, so yes is a step ahead of the USB from the S-10. There are also two other benefits, firstly it has all the D2D circuitry from the S-10 removed so potentially less noise. Secondly a smaller chassis should = less resonance.
The difference between the X100 and the W20 is immediately obvious and easily justifies the premium of the W20 if it remains within budget. The W20 offers a more robust bottom end, exhibiting greater extension, more body, and also more control of the bass which is welcome. The soundstage widens without compromising on imaging. The presentation is smoother and more refined - vocals gaining a more organic nature. The top end sounds again more extended and yet smoother. You certainly wouldn't be disappointed with the X100, but I wouldn't demo a W20 unless your budget allows.
These are not "expensive computers", they are purpose built digital transports. No they don't have a dac, some people say this like it's a bad thing. For the same reason there is no CD drive to rip music, it's a completely SOTA component. Why would you want to be limited to an internal dac? The Lumin has one, and it's good but not great, so for me a feature that is wasted (and yes have had extensive time with a Lumin in my system too). There are not many digital transports with dual AES/EBU digital outputs to make optimal use of dual mono dacs, nor do many have word clock sync capabilities. When you experience the benefits of a clock sync, you'll understand. The W20 is not designed to be a value-for-money proposition like some players are, it's designed to be the best digital transport available at whatever cost. As a transport it bests my Esoteric K-01, that's proof enough for me.