These have it draw-backs too. They ("the firm") may have opinion on your trading style, risk parameters, they may try to influence your trading, etc. Investors in CTA/HF will mostly leave you alone to do your own thing inside the given risk mandate. They care only about monthly, quarterly and annual returns.
Goldman will look at you if your a quant with an mba, but bottom line at the end of the day, you ill make just as much at a prop firm as you will at goldman if you arent profitable...... atleast the prop firm will give you a few more days to bleed your account dry.
He's not "prop" in that sense of the word - my understanding is that he trades his own account. Goldman isn't a consideration for him unless somehow top tier IB firms are now telecommunicating.