This is a question with an answer that will be different for each borrower. Keep in mind that the whole idea of refinancing is to save money. In most cases, borrowers can save up to 3% in interests rates if their credit score has improved since they took the loans the first time.
Getting an estimate will not take much time, with most online alternatives you would be able to calculate your savings online and in a matter of minutes. I actively recommend individuals to know at all times where they are standing and also if the circumstances are changing on their benefit or against them.
Don't forget that under certain conditions it might be better to sustain the current plans as you would get affected in the long term of the loan. As mentioned before, avoid at all cost sacrificing your future for your gain today.