I've bought some of those, knowing they were potentially sketchy, for applications that don't matter (like NintendoDS flash carts, or Raspberry Pi projects) and I've mostly been impressed with them. They have worked, and had most/all of their listed capacity at most of their advertised read/write speed.

Then again, I was only buying low-capacity ones, like 16-32GB max, and haven't used any for many write cycles, so idk if they hold up.

But it was worth it, for me, to get a steep discount on chips for tinkering projects.

But for my 1TB chip for my Deck, I went through the verification process with the manufacturer to confirm it was a legit chip while it was still in the return window!