As pointed out, China laws are ambiguous. If polox were to go bust one day, traders and lenders could file legal actions against the site and there is a remote hope of getting some funds back.
You can't do the same for hao btc. It is up to potential investors to weigh the risk. A higher interest rate should not be the sole consideration.
This is the main problem I have with most non EU/US companies. Most of them have a different regulation and laws. If they (For what ever reason) become a victim of the governement, any third party will lose their money, without any oppertunity to fight is legally.
Obviously i use those parties in China but I tried to keep my max. balance less then 1 bitcoin, to minimize a potential lose.