I had a set of Toseek ones for a while, no complaints other than they made a really disturbing cracking noise on drops. It wasn’t the carbon, it was just the brake hose clanging against it, but enough to make me let out a little poop of fear the first few times 😂 . Sold them on nd never heard anything more so presumably they either killed the new owner or they were also happy with them.
I did look into it at the time (I think it shows it on the test certificates in the listings?) and they’re just another brand name thought up by one of the factories that have been selling direct for a couple of decades now, so it’s not some flybynight operation.