I must admit that I have only had positive experiences with Chinese valve amps .... a Ming Da MC34-A integrated and a Consonance M100 Plus - a 300B integrated. The latter being one of the very few components I regret selling on - a wonderful amp. And now my OTLs. Yup, 3 out of 3 positive Chinese amp experiences!

No, I've not tried Atma Sphere - I've read about them in Stereophile and TAS, though .... long rows of power tubes! Weigh a ton and cost a lot of ££££. I'm happy enough with my Chinese OTLs at a small fraction of the cost.