Its true that open.btc is a UIA and is similiar to btc on an exchange like poloniex or bittrex. If someone steals the btc in deposit, your funds may be at risk. As part of the bitshares network, open.btc has does have several advantages over traditional exchanges. For additional protection from counterparty risk, one can trade open.btc for for bitBTC(listed as BTC). BitBTC is one of several assets backed by BTS(the native token on bitshares) and thus is not subject to the same counterparty risk as the gateway tokens(open.btc trade.btc etc).
In addition to bitBTC, there are assets for other cryptos or commodities of interest. When actively trading open.btc on markets with these bitAssets or SmartCoins one is potentially exposed to half of the counterparty risk of a normal exchange as only one of the two assets is backed by crypto held by the gateway. So by using the Openledger/bitshares you should be able to reduce your exposure to counterparty risk.
I am not sure if many people understood what you said. If they did you must have had many more upvotes ;) Thanks for a good answer.
@lafona. I know this is a really old post. I hope you are still around to reply? I didn’t understand what you said. What is the difference between open.btc and bit.btc and why is the price different?