The twin x has tb3 and has a newer generation of converters.
Pretty sure there is a USB3 version of the X...?
I've read the specs on the converters, but with audio gear, I only care about what it sounds like, and in my experience, published specs for converters and preamps don't tell me much of anything about how musical/good they sound (within reasonably similar price ranges and product tiers, of course).
I figured it's probably a longshot that anyone has heard both the Silver Twin Duo and the black X Twin Duo, or if they did, that it's burned into their memory enough to really say much.
I can get the Silver
considerably cheaper, is all. Unless the X is markedly better sounding in a material way, there is no real point, since I'm primarily just in need of the digital inputs (I'm retiring/selling my previous digital-capable interfaces)