The BitMEX products are great. Generally, the LXDX core team are fans. But LXDX don't like auto-deleveraging an don't like socialized losses. LXDX are going about that differently; their variant is quite different — they don't do auto liquidations, they don't do everything denominated in BTC. LXDX want to give new—and better—products to the community. Additionally LXDX are fully compliant with the laws of Malta (where they operate out of) and the SEC and the jurisdictions with which LXDX interact with.

Also, you can't short sell up/down on Bitmex.  You can short sell warrants on LXDX!