I don't.

Hifiman QA is exceptionally bad, and they tend to not stand by their warranty, and their US repair facility is just some dude's house.

The threads on /r/headphones over Hifiman shafting them are numerous.

Disclaimer: I too had a Hifiman pair, they sounded great, but their physical design just didn't hold up to daily use, no matter how much I babied them.