I am late to this post, but have had a Gustard X20u for 8 days now with signal running constantly and even performed a few simple mods. I have not compared this dac to anything other than my previous dac a NAD M51 which I had sounding just fabulous in my system. I bought the Gustard because of many favorable comments on it and Marty's comments were a big part of that and the ability to upsample to 2x DSD via USB. The X20 now has over 160 hours of signal running thru it and as I mentioned I did perform some basic mods, which take this dac to an even higher level, Ric from Tweakaudio.com is posting these on his site. This dac now crushes my NAD and competes with my very nice analog rig SME30mk2, sme Vd arm, dynavector XV1s cart. Marty said it well "Dac shines in minute details and depth resolution". Density of information as I call it, by that I mean vinyl can give all performers even to the sides and back a 3d, very real palpable presence. Digital usually gets that on the main performer but the side and back performers, even tho very transparent and dynamic they are always more 2d than the front lead performer. The Gustard with these basic mods now gives me that "density of information" 3d images from front to back, side to side. very transparent, dynamic and involving. I have never enjoyed music more than I do now.
So I am not surprised this dac did so well in his "unscientific" shootout. It definitely punches, way higher than it's price.