Thank you all for your answers, What is significant benefits?

A general rule, subject to lender interpretaion, is you need to "save" (in projected interest payments over the life of the loan, by a lower rate, or shorter term, or by additional cash out), 5 times the cost of the refinance. This rule was put into effect to limit "churning", which is the rapid sequential refinance of a property, thus reducing the remaining borrower equity, and only benefiting the greedy loan broker.