Student loan refinancing is a one-way trade. You exchange the rate you have now for a lower rate, but federal protections are insurance you can't buy back. For high-earning, stable-income borrowers with no public-service career plans, refinancing typically saves money. For borrowers in early-career instability, considering public service, or possibly needing income-driven repayment, the federal protections are usually worth the higher rate.
Most readers should start with the refinance vs consolidation analysis, then narrow to the comparison of specific lenders. Medical and dental professionals have specialized options at Best Student Loan Refinance that materially beat the broad-market options.