Advantages of Bipolar over Mosfets Transistors: Bipolar transistor is much more faster thank Mosfet. and in case when frequency is getting higher and higher the switching power of Mosfet could increase the switching power of Bipolar. Mosfet is good when you are using in digital design, because in logic stat 0 and 1 they have a very little leakage current. but even now when we have already Mosfet with 0.22nm channel length the leakage is already significant.