after my first go with it I haven't been brave enough to try it again.
As a general rule, I don't set stops. Too many ForEx brokers have been caught with bogus "liquidity squeezes" that result in artificial price spikes, set slippage, and other dirty tricks for me to mess with it. (see MetaTrader4 Virtual Dealer Plugin)
Since there is a distinct potential for low liquidity at Bitcoinica, I tend to not use Market orders unless I've watched the price bot for a good while, and know exactly what's happening. Getting hit with $0.10 of slippage on a market order hurts. When carefully executed in alignment with the price bot/real order depth, they work well. Since a stop executes a market order, unsupervised, I'm wary, and don't use. There's too much chance for spikes to stop you out, without any dirty tricks, that it seems it's just asking to give someone else your money