You're getting HE-6 technicalities with Susvara tonality, which is not the same as getting a Susvara on the cheap. Soundstage will be notably smaller, fine details won't be quite as delicate, but dynamics should be impressive.I just saw these on Taobao. They looked... darned interesting. The listing says I shouldn't blind-buy these if I don't have experience with the Susvara or the HE6 (which i don't) but I have some experience with the HD800s, the Audeze line-up and the Arya. For like 450 bucks they seem like a great pair of headphones if it sort of approaches Susvara level, what's holding it back from being a solid recommendation?
Following on from other comments about amps: you need about 3-4 W to get these working well, because they'll have substantial current demand. Tubes won't help you here.