The Topping D90 is a phenomenal dac! One of the best dac’s at any price IMHO.... Have had it for 3 weeks now, and its imaging, transparency to the source, detail, dynamic snap, tonal accuracy, and impact are jaw dropping .... at $699 its shockingly good...It is still has somewhat caramel like coloring like most AKM chips do, but to a much less extent.. Also, somewhat has very grayish background, as opposed to the complete black. Its very system and cable dependent I ’d say.... My Cardas Golden Crosses are somewhat laid back already, and I ve used a custom "high" resolution interconnect in place of the Cardas Golden Cross IC, and the D90 readily revealed a new sonic signature of the new item in the system... Also I ve been using it as a preamp as well via its balanced outs, into the Classe Dr-3 Class A amplifier (which itself is also somewhat on the darkish side in some set ups) and I hear D90 is even more transparent as a stand alone dac if used with high quality preamp, but which option is more transparent is highly system dependent as usual... Also been burning in the Gustard A22, uses 2 AKM 4499 ,with much beeifier power supplies, different parts, and uses different layout (by the way, a HUGE shout out to CJ at the Apos shop for getting me this unit in 3 days during a lock down in China!!!! Exemplary service and attitude of guys at Apos)... Too early to comment definitively on the Gustard dac, but I d say we have hit the golden age of performance where dacs at relatively small sums (compared to 10 of thousands $ in the past) provide awesomely musical and enjoyable sound to music lovers at any budget!!!