difference between conventional vs FHA streamline refinance

[Jorge Lerdo de Tejada]

I have been paying a 30yr FHA loan at 3.7% for 6 year. I am interested in knowing if refinancing will be worth it, since i believe the equity in the house could be higher than 20% (therefore no Mortgage insurance?). Also interested in knowing if I refinance what is the difference between a conventional loan re-finance and a FHA Streamline refinance?

Thank you for your help in advance!