Three separate times I have gone to Segal Roitman, who only represent labor unions and employees, and who are great. Twice they gave me pro bono advice about disability discrimination and shenanigans, once I hired them to evaluate and help me modify a contract. The lawyer who first gave me advice there is now an Obama-appointed district court judge and is sometimes in the news being pretty great. (ETA: She actually gave me advice specifically about a severance agreement, which was namely "they can't enforce X, and even though you're in the right if you decide to sue over Y you're incredibly unlikely to win, so unless you're planning on doing the hail mary lawsuit, take their money and walk away." Which was honestly great advice.)