The Financial Backer may be a government, galactic corporation, even several small corporations. Whoever they are while the interest rate may be smaller they will have certain strings attached both during and after the race’s conclusion. Though the sponsor can also be of assistance to the crew in the sponsor’s own areas of influence as they have some interest in the group’s success even if only their bets
The Loan Shark with the highest interest rate the loan shark also cares very little about what you do and how you do it as long as they are paid. Offering the most independence and full Independence once paid.
The Crime Boss is the seedy figure putting up the money while his influence may deter certain pirates or other shady types from taking advantage. Rivals and customs may be harder on you if trouble hits you may get help but will be racking up owed favors and credits as the Crime boss tries to ensure you stay under his thumb even after the loan is paid.