Trillium is probably the only legit one...all the others close after 1 or 2 yrs....First New York Securities opened an office in Boca Raton but last time I checked they said they were closing it due to lack of talent.
lack of talent? why would a profitable trader go to a prop firm to pay them commissions, desk fee, software fee, chair fee, coffee fee, rental fee, toilet fee, while he can sit at home collecting money paying no fees to nobody?
I started trading in South Florida, I was offered a true prop deal where I had to put up $0 and was trained by a very profitable trader. But in our office we had a few traders and retirees who I assume liked to trade in a group environment or to get away from their wives. This was also late 90's early 00' so there was not as many online brokers to trade with and I believe the cost was very high to trade with the ones who were available. To finally answer your question I think the reason someone would go prop now would be either or all 1. Leverage 2. Environment 3. Capital Outlay.