One year ago, I bought 2 Topping products DOA. No problem with Amazon, but one year later I cannot resist and I am ordering again some Topping products.
Frankly speaking, two years ago I've seen Gustard products and found the name is ridiculous (sound like mustard for me), surely bad products from China. Don't get me wrong, I am not saying China is only producing bad products, but the country was not, by this time, identified as great audio gear producer.
Two years later, surely because of ASR, I bought plenty of Chinese products from SMSL, Sabaj, Topping, and now Mustard, err, sorry, Gustard.
I understand your pretty bad impression, but things change.
Also, I lived in China, loved the country and the people, and I am more than happy to see these Chinese brands send some lessons to the audiophile community.