Monies in these type of acct are only as safe as the risk manager and type of trader that the group brings on. Most of these sub acct are pooled with stock traders who go home flat. That limits your risk. I will only do business with a group who does have risk management and that manager does not trade, as who would be watching him. Almost all the firm that came down where due to the management getting hurt bad in the market.
I have a stock acct with GTT/PCT and have had great service. Cameron does a great Job, I also trade through a JBO acct with $5 Million put up by the managing member plus traders capital, so that sounds great, but is managed more like a Micro Hedge Funds and has more neutral/ delta option traders with overnight exposure. The only reason I trade with this group is because the management does not trade and have great risk management, a high buying and only work with quality traders. Do your due diligence.
Need leverage, go with quality, not size or big name. More traders usually means less service and more risk due to pure buying power spread over 400 traders. Ask for the capital per trader ratio. That will offer the quality and risk factor of your funds. Good luck