There's a guy in Austria who used a Chinese knockoff HX35 for 15000 miles with no issue, but the shaft play was awful. Dyno'd 330 hp on a 603.
I have a genuine HX30 that was made at the Holset factory in China, it is fine.
I would steer clear of alibaba or Ali express, eBay can be hit or miss but don't even look at a new turbo for less than $300 in my opinion